Prevent replicas from sending commands that interact with keyspace (#8868)
Prevent replicas from sending commands that interact with keyspace (#8868)

This solves an issue reported in #8712 in which a replica would bypass
the client write pause check and cause an assertion due to executing a
write command during failover.

The fact is that we don't expect replicas to execute any command other
than maybe REPLCONF and PING, etc. but matching against the ADMIN
command flag is insufficient, so instead i just block keyspace access
for now.

(cherry picked from commit 46f4ebbe842620f0976a36741a72482620aa4b48)

ctripcorp/redis,ctripcorp/redis,ctripcorp/redis,ctripcorp/redis