fix(RemoteConferenceEventHandler): remove listener only if core exists + add `me` in main db tests

src/conference/handlers/remote-conference-event-handler.cpp

@@ -233,7 +233,12 @@ Object(*new RemoteConferenceEventHandlerPrivate) {
 
 RemoteConferenceEventHandler::~RemoteConferenceEventHandler () {
 	L_D();
-	d->conf->getCore()->getPrivate()->unregisterListener(d);
+
+	try {
+		d->conf->getCore()->getPrivate()->unregisterListener(d);
+	} catch (const bad_weak_ptr &) {
+		// Unable to unregister listener here. Core is destroyed and the listener doesn't exist.
+	}
 
 	if (d->lev)
 		unsubscribe();

src/core/core-accessor.cpp

@@ -56,7 +56,7 @@ shared_ptr<Core> CoreAccessor::getCore () const {
 	shared_ptr<Core> core = d->core.lock();
 	if (!core) {
 		lWarning() << "Unable to get valid core instance.";
-		throw std::bad_weak_ptr();
+		throw bad_weak_ptr();
 	}
 
 	return core;