Hardening/false leaks

### Description
Fixed the new SIGSEGV  - moved the call to mongDisconnect to a higher level.
Fixed the two leaks (197 bytes each) - deleting triggeredSubscriptions filtered by throttling.

In theory you don't need do this given that processSubscription() manages to release individually each element in the map. However, I think it doesn't hurt.

However, I'd add the following comment about this line:

"Although processSubcriptions() is supposed to release the dynamic memory associated to each TriggeredSubscription element in the map, an invocation to releaseTriggeredSubscriptions() is a safe-guard that doesn't hurt"

or something like that.