Adds missing rabbit_userid to trove configs

- rabbit_userid was only updated in trove.conf leaving other
  trove configuration files not having this value.
- Trove service setup was broken because of this.
- Added rabbit_userid to trove-taskmanager.conf,
  trove-conductor.conf and trove-guest.conf.

Change-Id: I60bd160600ec4a02c94ee5e33e4bc91c9f2aa2ed
Closes-Bug: #1402227
Merge "Adds missing rabbit_userid to trove configs"
Merge branch 'master' of https://github.com/openstack-dev/devstack