Allow AUTH when Redis is busy because of timedout Lua script.
Allow AUTH when Redis is busy because of timedout Lua script.

If the server is password protected we need to accept AUTH when there is
a server busy (-BUSY) condition, otherwise it will be impossible to send
SHUTDOWN NOSAVE or SCRIPT KILL.

This fixes issue #708.

JackieXie168/redis,JackieXie168/redis,JackieXie168/redis,JackieXie168/redis