Fix logout current connection crash

Make sure that the neochat can handle switching connection when the current one is logged out. This is mostly about using QPointer to handle use after free issues due to room objects being deleted.

src/controller.cpp

@@ -156,6 +156,15 @@ void Controller::addConnection(NeoChatConnection *c)
         c->saveState();
     });
     connect(c, &NeoChatConnection::loggedOut, this, [this, c] {
+        if (accounts().count() > 1) {
+            // Only set the connection if the the account being logged out is currently active
+            if (c == activeConnection()) {
+                setActiveConnection(dynamic_cast<NeoChatConnection *>(accounts().accounts()[0]));
+            }
+        } else {
+            setActiveConnection(nullptr);
+        }
+
         dropConnection(c);
     });
     connect(c, &NeoChatConnection::badgeNotificationCountChanged, this, &Controller::updateBadgeNotificationCount);