Security: update Lua struct package for security.
Security: update Lua struct package for security.

During an auditing Apple found that the "struct" Lua package
we ship with Redis (http://www.inf.puc-rio.br/~roberto/struct/) contains
a security problem. A bound-checking statement fails because of integer
overflow. The bug exists since we initially integrated this package with
Lua, when scripting was introduced, so every version of Redis with
EVAL/EVALSHA capabilities exposed is affected.

Instead of just fixing the bug, the library was updated to the latest
version shipped by the author.

oranagra/redis,nnog/redis,GitHubMota/redis,PKRoma/redis,charsyam/redis,yossigo/redis,ofirluzon/redis,GitHubMota/redis,spinlock/redis,pmem/redis,pmem/redis,spinlock/redis,nnog/redis,nnog/redis,neomantra/redis,PKRoma/redis,pmem/redis,PKRoma/redis,ofirluzon/redis,soveran/redis,antirez/redis,soveran/redis,PKRoma/redis,oranagra/redis,ofirluzon/redis,charsyam/redis,neomantra/redis,yossigo/redis,soveran/redis,ctripcorp/redis,soveran/redis,soloestoy/redis,antirez/redis,GitHubMota/redis,spinlock/redis,PKRoma/redis,ofirluzon/redis,ofirluzon/redis,neomantra/redis,yossigo/redis,charsyam/redis,soloestoy/redis,ctripcorp/redis,oranagra/redis,yossigo/redis,charsyam/redis,yossigo/redis,neomantra/redis,spinlock/redis,soloestoy/redis,GitHubMota/redis,pmem/redis,neomantra/redis,soloestoy/redis,soloestoy/redis,antirez/redis,charsyam/redis,nnog/redis,ctripcorp/redis,ctripcorp/redis,antirez/redis,oranagra/redis,oranagra/redis