lua_struct.c/getnum: throw error if overflow happen
lua_struct.c/getnum: throw error if overflow happen

Fix issue #2855

GitHubMota/redis,itamarhaber/redis,charsyam/redis,yossigo/redis,izhoujie/redis,colstrom/redis,shreesundara/redis,oranagra/redis,shreesundara/redis,itamarhaber/redis,zguangyu/redis,Markgorden/redis,kensou97/redis,OmarQunsul/graph-redis,ton31337/redis,antirez/redis,GitHubMota/redis,neomantra/redis,OmarQunsul/graph-redis,h0x91b/redis,kensou97/redis,ofirluzon/redis,yossigo/redis,nnog/redis,zguangyu/redis,oranagra/redis,PKRoma/redis,YongMan/redis,itamarhaber/redis,nnog/redis,pmem/redis,weizijun/redis,arijitvt/redis,spinlock/redis,ofirluzon/redis,zguangyu/redis,izhoujie/redis,soloestoy/redis,kensou97/redis,h0x91b/redis,ton31337/redis,izhoujie/redis,rouzier/redis,antirez/redis,oranagra/redis,PKRoma/redis,h0x91b/redis,dreamquster/redis,neomantra/redis,ctripcorp/redis,Markgorden/redis,OmarQunsul/graph-redis,Markgorden/redis,izhoujie/redis,charsyam/redis,arijitvt/redis,h0x91b/redis,spinlock/redis,soloestoy/redis,Sciumo/redis,charsyam/redis,soveran/redis,rouzier/redis,GitHubMota/redis,dreamquster/redis,antirez/redis,ctripcorp/redis,YongMan/redis,yossigo/redis,YongMan/redis,badboy/redis,arijitvt/redis,dreamquster/redis,soveran/redis,zguangyu/redis,badboy/redis,itamarhaber/redis,ofirluzon/redis,ofirluzon/redis,neomantra/redis,soloestoy/redis,rogerchina/redis,oranagra/redis,ctripcorp/redis,soloestoy/redis,pmem/redis,colstrom/redis,Sciumo/redis,weizijun/redis,antirez/redis,Sciumo/redis,shreesundara/redis,ofirluzon/redis,hgl888/redis,spinlock/redis,oranagra/redis,weizijun/redis,dreamquster/redis,charsyam/redis,PKRoma/redis,pmem/redis,charsyam/redis,badboy/redis,sunheehnus/redis,sunheehnus/redis,neomantra/redis,yossigo/redis,spinlock/redis,soveran/redis,nnog/redis,ctripcorp/redis,ton31337/redis,yossigo/redis,badboy/redis,arijitvt/redis,nnog/redis,YongMan/redis,neomantra/redis,GitHubMota/redis,rouzier/redis,rogerchina/redis,Sciumo/redis,hgl888/redis,colstrom/redis,sunheehnus/redis,Markgorden/redis,ton31337/redis,weizijun/redis,shreesundara/redis,rogerchina/redis,rogerchina/redis,kensou97/redis,soloestoy/redis,sunheehnus/redis,PKRoma/redis,hgl888/redis,hgl888/redis,soveran/redis,OmarQunsul/graph-redis,pmem/redis,PKRoma/redis,rouzier/redis,colstrom/redis