Fail when ssl parameters are missing and rabbit_use_ssl is set to true

This commit causes the run to fail is rabbit_use_ssl parameter is set
to true but the ssl related parameters remains undef.

Change-Id: I3784839dca59a06c1155e845df5e62625ea668f0
Allow configuring the rbd keyring name

Change-Id: I7342ec1337cf86c0e4bc66b1788e65c53b2878ce
Merge "Allow configuring the rbd keyring name"