Changed exception handling in AzureServicebusSubscriptionNotifier to catch more generic MessagingException.

In some situations, azure servicebus throws an exception that get's wrapped in a MessagingException, not in the MessagingCommuncationException.  Since these exceptions would then be unhandled, the worker process grinds to a halt.
Merge pull request #147 from Erwinvandervalk/develop

Changed exception handling in AzureServicebusSubscriptionNotifier to catchch more generic MessagingException.