Add 'euph.rooms.<name>.force_username' config option

src/ui/euph/room.rs

@@ -105,6 +105,7 @@ impl EuphRoom {
             let (room, euph_room_event_rx) = euph::Room::new(
                 store,
                 self.config.username.clone(),
+                self.config.force_username,
                 self.config.password.clone(),
             );