Removed redundant titlescreen control blocks in MP cases

No need to continue since we're already at the end of the loop. Regardless of the return value,
we want to loop again, in which case break handles that just fine.

src/wesnoth.cpp

@@ -911,21 +911,15 @@ static int do_gameloop(const std::vector<std::string>& args)
 			return 0;
 		case gui2::dialogs::title_screen::MP_CONNECT:
 			game_config::set_debug(game_config::mp_debug);
-			if(!game->play_multiplayer(game_launcher::mp_mode::CONNECT)) {
-				continue;
-			}
+			game->play_multiplayer(game_launcher::mp_mode::CONNECT);
 			break;
 		case gui2::dialogs::title_screen::MP_HOST:
 			game_config::set_debug(game_config::mp_debug);
-			if(!game->play_multiplayer(game_launcher::mp_mode::HOST)) {
-				continue;
-			}
+			game->play_multiplayer(game_launcher::mp_mode::HOST);
 			break;
 		case gui2::dialogs::title_screen::MP_LOCAL:
 			game_config::set_debug(game_config::mp_debug);
-			if(!game->play_multiplayer(game_launcher::mp_mode::LOCAL)) {
-				continue;
-			}
+			game->play_multiplayer(game_launcher::mp_mode::LOCAL);
 			break;
 		case gui2::dialogs::title_screen::RELOAD_GAME_DATA:
 			gui2::dialogs::loading_screen::display([&config_manager]() {