RDB: Apply fix to rdbLoadMillisecondTime() only for new RDB versions.
RDB: Apply fix to rdbLoadMillisecondTime() only for new RDB versions.

This way we let big endian systems to still load old RDB versions.
However newver versions will be saved and loaded in a way that make RDB
expires cross-endian again. Thanks to @oranagra for the reporting and
the discussion about this problem, leading to this fix.

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