Corrected set_permissions

The provider doesn't use the syntax we need for the default version
of rabbitmq the package installs.

This is a temporary work-a-round, so we do not need to manually
twiddle rabbit permissions on deployment.  Once matt's changes
are merged upstream will switch back.

   https://github.com/mattray/rabbitmq/tree/COOK-2201
Merge pull request #1 from retr0h/working

Corrected set_permissions