Change the default for rabbitmq back to ha-mode: all

Change the default for rabbitmq back to ha-mode: all

In change Ib62001c03e1e08f58cf0c6e0ba07a8879a584084 we switched the
rabbitmq queues HA mode from ha-all to ha-exactly. While this gives us a
nice performance boost with rabbitmq, it makes rabbit less resilient to
network glitches as we painfully found out via
https://bugzilla.redhat.com/show_bug.cgi?id=1441635.

This is the THT part of the change that changes the default to
ha-mode: all.

Closes-Bug: #1686337
Co-Authored-By: Damien Ciabrini <dciabrin@redhat.com>
Co-Authored-By: John Eckersberg <jeckersb@redhat.com>
Change-Id: I7afcf2b3c8deb13fc2134e4cae9c06a44e775384
Depends-On: I9a90e71094b8d8d58b5be0a45a2979701b0ac21c