BUG #9136: pg_is_xlog_replay_paused() should not need Superuser

The following bug has been logged on the website:

Bug reference:      9136
Logged by:          Renato Ramonda
Email address:      sys-milan@statpro.com
PostgreSQL version: 9.2.6
Operating system:   Ubuntu 12.04
Description:

The admin function pg_is_xlog_replay_paused() is read only and can be useful
for monitoring, as such it should NOT require superuser privileges (as it
does now).

For reference, the read-only functions for monitoring the replication delay
such as pg_current_xlog_location can be executed without superuser
privileges (as remarked by the official documentation here
http://www.postgresql.org/docs/9.1/static/functions-admin.html )