engine: remove Quota audit log message when DC is in enforce mode.

When DC Quote mode enforced is selected and a VM does not have a quota
definitions, a log is printed the the DC is in audit mode.
Removing that log message.

Change-Id: I795f28ae247b0e78d7d785b37a3da834086a1e30
Bug-Url: https://bugzilla.redhat.com/1102613
Signed-off-by: Kobi Ianko <kobi@redhat.com>