DE1262: Fix rabbitmq-server going away.

When the logs are rotated, bluepill chef-server restart winds up
getting restarted several times in quick succession.  This can cause
bluepill to get trapped in a state where it thinks Rabbit is up when
it is not.

To work around this, have logrotate make a copy of the current log and
then truncate it.  This gets rid of the need to have the services
restart in order to continue logging messages.
Merge pull request #568 from VictorLowther/pull-req-release-mesa-1.6-master-271754a47a313e1f65eead7f90b2b327783c48a2

Fix DE1262 -- Rabbitmq server intermittently going away. [1/1]