Postgresql - Minor version upgrade 9.3.5 to 9.3.6 on Ubuntu

I am two servers: A & B. My master database is running on A and the version is 9.3.5. It's replica is running on B and the version is 9.3.6. I am trying to use B as UPSTREAM slave, and trying to start another database (on different port) which would be replica of B. So the desired setup is like this: A:5432(master) -> B:5432(slave-upstream) -> A:5433(slave-downstream)

When I try to start A:5433(slave-downstream), it says:

FATAL:  could not connect to the primary server: FATAL:  no pg_hba.conf entry for replication connection from host "5.6.7.8", user "replicator", SSL on
        FATAL:  no pg_hba.conf entry for replication connection from host "5.6.7.8", user "replicator", SSL off

I've following entries on B:

host    all             all             5.6.7.8/32       md5
host    replication     all             5.6.7.8/32       md5

I am suspecing the problem might be due to the difference of versions? If it's the case, how can I upgrade postgresql on A to 9.3.6?

Or anyother help?

Thanks