Cluster: SET-CONFIG-EPOCH should update currentEpoch.
Cluster: SET-CONFIG-EPOCH should update currentEpoch.

SET-CONFIG-EPOCH, used by redis-trib at cluster creation time, failed to
update the currentEpoch, making it possible after a failover for a
server to set its configEpoch to a value smaller than the current one
(since configEpochs are obtained using currentEpoch).

The bug totally break the Redis Cluster algorithms and protocols
allowing for permanent split brain conditions about the slots
configuration as shown in issue #1799.

CodeJuan/redis,josiahcarlson/redis,soloestoy/redis,YuraLukashik/redis,programmecat/redis,z-fork/redis,mumingv/redis,Sciumo/redis,jackyan/redis,thomasdarimont/redis,clamoriniere1A/redis,duanx/redis,YongMan/redis,linfangrong/redis,supasate/redis,gilala/hbjredis,cloudrain21/redis,hornen/redis,tanghaodong25/redis,soveran/redis,csuhawk/redis,4396/redis,OmarQunsul/graph-redis,StevenTsai/redis,wbailey5/redis,wbailey5/redis,clamoriniere1A/redis,mengzhejin/RedisStudy,GrimDerp/redis,StevenTsai/redis,Wangyao14cyy/redis,j0hnma/hszredis,simplestbest/redis,vincent-vivian-liu/redis,elkingtonmcb/redis,wprice/redis,j0hnma/szredis,h0x91b/redis,gaoxianglong/redis,netroby/redis,MOON-CLJ/redis,twskipper/redis,PKRoma/redis,tjschuck/redis,ctripcorp/redis,iandyh/redis,blackmady/redis,ton31337/redis,PKRoma/redis,huyuezheng/redis,cnbin/redis,alenslan/redis,ituncle/redis,arijitvt/redis,francischan714/redis,MasahikoSawada/redis,z-fork/redis,SyntaxStacks/redis,ofirluzon/redis,ipmobiletech/redis,Sciumo/redis,itamarhaber/redis,CodeJuan/redis,rouzier/redis,netroby/redis,Aaron1992/redis,yossigo/redis,tellapart/redis,gilala/redis,nuxeh/redis,pedigree/redis,MasahikoSawada/redis,arijitvt/redis,yuhc/redis-benchmark-enhanced,flashbuckets/redis,JoeWoo/redis,itamarhaber/redis,valdsJohn/redis,ouyangkongtong/redis,ton31337/redis,h0x91b/redis,vincent-vivian-liu/redis,jasonkying/redis,AALEKH/redis,GitHubMota/redis,xlzhan/redis,gilala/hredis,healerkx/redis,yuhc/redis-benchmark-enhanced,pmem/redis,mgk/redis,taoguan/redis,pcarrier/redis,mumingv/redis,shining-yang/redis,abhiklodh/redis,mengyou0304/redis,4396/redis,mingyaaaa/redis,z-fork/redis,mengyou0304/redis,xujunhai1991/redis,flashbuckets/redis,jasonkying/redis,charsyam/redis,aim-for-better/redis,riyan8250/redis,mcanthony/redis,ErikDubbelboer/redis,GrimDerp/redis,YongMan/redis,gilala/hredis,pcarrier/redis,yossigo/redis,badboy/redis,rogerchina/redis,zhcy/redis,190235047/redis,MasahikoSawada/redis,OmarQunsul/graph-redis,mgk/redis,tjschuck/redis,simplestbest/redis,xlzhan/redis,guker/redis,ctripcorp/redis,guker/redis,190235047/redis,francischan714/redis,cloudrain21/redis,roth1002/redis,JoeWoo/redis,AplayER/redis,wenxueliu/redis_comment,allengaller/redis,oranagra/redis,Wangyao14cyy/redis,GitHubMota/redis,kensou97/redis,zhcy/redis,wbailey5/redis,izhoujie/redis,j0hnma/szredis,seandsky/redis,davidradunz/redis,shining-yang/redis,xuguruogu/redis,ipmobiletech/redis,mattsta/redis,pedigree/redis,dreamquster/redis,antirez/redis,ton31337/redis,ncopa/redis,charsyam/redis,josiahcarlson/redis,j0hnma/hszredis,mengzhejin/RedisStudy,rogerlz/redis,seppo0010/rlite-server,NBSW/redis,PKRoma/redis,jackyan/redis,JoeWoo/redis,wujf/redis,ipmobiletech/redis,universsky/redis,citusdata/redis,tanghaodong25/redis,zhcy/redis,gilala/hredis,thomasdarimont/redis,soloestoy/redis,guker/redis,badboy/redis,kmiku7/redis,mumingv/redis,pedigree/redis,dayuoba/redis,shreesundara/redis,izhoujie/redis,StevenTsai/redis,kaushik94/redis,seppo0010/rlite-server,Aliceljm1/redis,zczhuohuo/redis,valdsJohn/redis,wangyikai/redis,francischan714/redis,cusspvz/redis,izhoujie/redis,jingjidejuren/redis,janekmi/redis,seppo0010/redis,narma/redis,holstvoogd/redis,ofirluzon/redis,guker/redis,itugs/redis,rogerchina/redis,modulexcite/redis,shining-yang/redis,PradheepShrinivasan/redis,abhiklodh/redis,hawkchch/redis,ofirluzon/redis,july2993/redis,oranagra/redis,thomasdarimont/redis,Aliceljm1/redis,fengshao0907/redis,supasate/redis,tellapart/redis,rouzier/redis,PradheepShrinivasan/redis,aim-for-better/redis,modulexcite/redis,huyuezheng/redis,nnog/redis,pmem/redis,CodeJuan/redis,rogerlz/redis,abhiklodh/redis,jackyan/redis,pmem/redis,universsky/redis,RepmujNetsik/redis,mingyaaaa/redis,hornen/redis,iandyh/redis,yossigo/redis,zguangyu/redis,j0hnma/szredis,wenxueliu/redis_comment,harrisonfeng/redis,narma/redis,charsyam/redis,wangyikai/redis,mengzhejin/RedisStudy,oranagra/redis,seandsky/redis,ytjiang/redis,j0hnma/hszredis,Soledad89/redis,wenxueliu/redis_comment,PradheepShrinivasan/redis,linfangrong/redis,SummonY/redis,a-pavlov/redis,Wangyao14cyy/redis,nnog/redis,nuxeh/redis,mcanthony/redis,josiahcarlson/redis,tanghaodong25/redis,hornen/redis,vincent-vivian-liu/redis,josiahcarlson/redis,mgk/redis,devaos/redis,pcarrier/redis,RepmujNetsik/redis,takeshineshiro/redis,arijitvt/redis,honestme/redis,itugs/redis,gilala/hredis,PradheepShrinivasan/redis,mverrilli/redis,wangyikai/redis,wenxueliu/redis_comment,healerkx/redis,a-pavlov/redis,oranagra/redis,jingjidejuren/redis,wprice/redis,ErikDubbelboer/redis,Aliceljm1/redis,YuanZhewei/redis,devaos/redis,taoguan/redis,mverrilli/redis,twskipper/redis,holstvoogd/redis,mverrilli/redis,valdsJohn/redis,takeshineshiro/redis,colstrom/redis,mgk/redis,ErikDubbelboer/redis,roth1002/redis,july2993/redis,linfangrong/redis,wujf/redis,hgl888/redis,ton31337/redis,fengshao0907/redis,elkingtonmcb/redis,janekmi/redis,seandsky/redis,SyntaxStacks/redis,shreesundara/redis,NBSW/redis,zhiliaoniu/redis,clamoriniere1A/redis,xuguruogu/redis,Wangyao14cyy/redis,hawkchch/redis,pcarrier/redis,gaoxianglong/redis,xujunhai1991/redis,harrisonfeng/redis,healerkx/redis,neomantra/redis,mcanthony/redis,ouyangkongtong/redis,gilala/bjredis,devaos/redis,190235047/redis,mumingv/redis,qiyang0221/redis,zguangyu/redis,ErikDubbelboer/redis,soloestoy/redis,ctripcorp/redis,hgl888/redis,seppo0010/rlite-server,huyuezheng/redis,riyan8250/redis,ouyangkongtong/redis,taoguan/redis,programmecat/redis,riyan8250/redis,ituncle/redis,saisai/redis,YuraLukashik/redis,xuguruogu/redis,iandyh/redis,nuxeh/redis,YuanZhewei/redis,programmecat/redis,ncopa/redis,jasonkying/redis,saisai/redis,devaos/redis,dreamquster/redis,kmiku7/redis,aim-for-better/redis,huyuezheng/redis,davidradunz/redis,colstrom/redis,GrimDerp/redis,ytjiang/redis,modulexcite/redis,yossigo/redis,antirez/redis,seppo0010/redis,honestme/redis,gilala/hbjredis,valdsJohn/redis,soloestoy/redis,fengshao0907/redis,hgl888/redis,MOON-CLJ/redis,zhiliaoniu/redis,mingyaaaa/redis,honestme/redis,arijitvt/redis,MasahikoSawada/redis,flashbuckets/redis,spinlock/redis,YuraLukashik/redis,rogerchina/redis,neomantra/redis,csuhawk/redis,atreeyang/redis,rogerlz/redis,ncopa/redis,soveran/redis,ctripcorp/redis,nnog/redis,pkdevbox/redis,netroby/redis,pkdevbox/redis,gilala/hbjredis,hedisdb/hedis,cusspvz/redis,soloestoy/redis,vincent-vivian-liu/redis,timothyohare/3rdPartySrc-redis,elkingtonmcb/redis,xlzhan/redis,allengaller/redis,ipmobiletech/redis,xujunhai1991/redis,gilala/redis,OmarQunsul/graph-redis,Markgorden/redis,oranagra/redis,zhiliaoniu/redis,SyntaxStacks/redis,StevenTsai/redis,SyntaxStacks/redis,wprice/redis,gaoxianglong/redis,j0hnma/szredis,gilala/bjredis,AplayER/redis,PKRoma/redis,Soledad89/redis,kaushik94/redis,qiyang0221/redis,cusspvz/redis,atreeyang/redis,Aaron1992/redis,CodeJuan/redis,colstrom/redis,supasate/redis,csuhawk/redis,soveran/redis,izhoujie/redis,mcanthony/redis,AALEKH/redis,zguangyu/redis,healerkx/redis,allengaller/redis,badboy/redis,duanx/redis,seppo0010/redis,dreamquster/redis,pkdevbox/redis,190235047/redis,atreeyang/redis,sunheehnus/redis,GitHubMota/redis,kensou97/redis,yuhc/redis-benchmark-enhanced,alenslan/redis,gilala/bjredis,taoguan/redis,duanx/redis,AALEKH/redis,jackyan/redis,brg-liuwei/redis,itugs/redis,saisai/redis,dayuoba/redis,j0hnma/hszredis,LongXQ/redis,rouzier/redis,hgl888/redis,spinlock/redis,janekmi/redis,SummonY/redis,dayuoba/redis,weizijun/redis,tjschuck/redis,Sciumo/redis,kensou97/redis,charsyam/redis,YongMan/redis,qiyang0221/redis,wujf/redis,neomantra/redis,sunheehnus/redis,aim-for-better/redis,antirez/redis,cusspvz/redis,AplayER/redis,iandyh/redis,YongMan/redis,supasate/redis,saisai/redis,ituncle/redis,xuguruogu/redis,Soledad89/redis,ofirluzon/redis,wprice/redis,a-pavlov/redis,harrisonfeng/redis,RepmujNetsik/redis,Aaron1992/redis,mengyou0304/redis,OmarQunsul/graph-redis,xlzhan/redis,ouyangkongtong/redis,tellapart/redis,dreamquster/redis,LongXQ/redis,tanghaodong25/redis,SummonY/redis,hedisdb/hedis,zczhuohuo/redis,harrisonfeng/redis,AplayER/redis,itamarhaber/redis,mengzhejin/RedisStudy,AALEKH/redis,ytjiang/redis,thomasdarimont/redis,timothyohare/3rdPartySrc-redis,abhiklodh/redis,blackmady/redis,LongXQ/redis,SummonY/redis,july2993/redis,z-fork/redis,Sciumo/redis,takeshineshiro/redis,cnbin/redis,badboy/redis,RepmujNetsik/redis,zczhuohuo/redis,zczhuohuo/redis,riyan8250/redis,kaushik94/redis,timothyohare/3rdPartySrc-redis,modulexcite/redis,neomantra/redis,Markgorden/redis,gilala/redis,roth1002/redis,zguangyu/redis,citusdata/redis,twskipper/redis,ituncle/redis,shreesundara/redis,wangyikai/redis,janekmi/redis,brg-liuwei/redis,ncopa/redis,hawkchch/redis,Markgorden/redis,neomantra/redis,4396/redis,mattsta/redis,hornen/redis,duanx/redis,hawkchch/redis,csuhawk/redis,seppo0010/redis,linfangrong/redis,atreeyang/redis,takeshineshiro/redis,mengyou0304/redis,mingyaaaa/redis,twskipper/redis,rogerchina/redis,pedigree/redis,honestme/redis,Soledad89/redis,xujunhai1991/redis,july2993/redis,cnbin/redis,Markgorden/redis,rogerlz/redis,rouzier/redis,charsyam/redis,roth1002/redis,zhcy/redis,wbailey5/redis,soveran/redis,gilala/hbjredis,narma/redis,flashbuckets/redis,alenslan/redis,hedisdb/hedis,yuhc/redis-benchmark-enhanced,MOON-CLJ/redis,cloudrain21/redis,shining-yang/redis,sunheehnus/redis,citusdata/redis,spinlock/redis,GrimDerp/redis,davidradunz/redis,itugs/redis,weizijun/redis,timothyohare/3rdPartySrc-redis,fengshao0907/redis,programmecat/redis,gaoxianglong/redis,holstvoogd/redis,alenslan/redis,simplestbest/redis,h0x91b/redis,jingjidejuren/redis,YuraLukashik/redis,Aliceljm1/redis,dayuoba/redis,seandsky/redis,ytjiang/redis,4396/redis,yossigo/redis,kmiku7/redis,JoeWoo/redis,brg-liuwei/redis,antirez/redis,francischan714/redis,YuanZhewei/redis,jasonkying/redis,brg-liuwei/redis,YuanZhewei/redis,gilala/bjredis,simplestbest/redis,elkingtonmcb/redis,pmem/redis,NBSW/redis,blackmady/redis,davidradunz/redis,zhiliaoniu/redis,weizijun/redis,spinlock/redis,clamoriniere1A/redis,a-pavlov/redis,citusdata/redis,cloudrain21/redis,blackmady/redis,shreesundara/redis,hedisdb/hedis,ofirluzon/redis,kmiku7/redis,colstrom/redis,PKRoma/redis,holstvoogd/redis,gilala/redis,tellapart/redis,kaushik94/redis,GitHubMota/redis,mverrilli/redis,wujf/redis,Aaron1992/redis,weizijun/redis,netroby/redis,h0x91b/redis,NBSW/redis,qiyang0221/redis,universsky/redis,universsky/redis,pkdevbox/redis,seppo0010/rlite-server,nnog/redis,allengaller/redis,tjschuck/redis,kensou97/redis,cnbin/redis,jingjidejuren/redis,nuxeh/redis,mattsta/redis,LongXQ/redis,itamarhaber/redis,sunheehnus/redis