Ensure slots are rechecked on EXEC.
Ensure slots are rechecked on EXEC.

Fixes #2515.

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