fix: crash that could occur when force-closing 7tv/bttv live updates (#6197)

src/providers/liveupdates/BasicPubSubManager.hpp

@@ -402,23 +402,23 @@ private:
         return false;
     }
 
+    std::vector<Subscription> pendingSubscriptions_;
+    std::atomic<bool> addingClient_{false};
+    ExponentialBackoff<5> connectBackoff_{std::chrono::milliseconds(1000)};
+
+    liveupdates::WebsocketClient websocketClient_;
+    std::unique_ptr<std::thread> mainThread_;
+    OnceFlag stoppedFlag_;
+
     std::map<liveupdates::WebsocketHandle,
              std::shared_ptr<BasicPubSubClient<Subscription>>,
              std::owner_less<liveupdates::WebsocketHandle>>
         clients_;
 
-    std::vector<Subscription> pendingSubscriptions_;
-    std::atomic<bool> addingClient_{false};
-    ExponentialBackoff<5> connectBackoff_{std::chrono::milliseconds(1000)};
-
     std::shared_ptr<boost::asio::executor_work_guard<
         boost::asio::io_context::executor_type>>
         work_{nullptr};
 
-    liveupdates::WebsocketClient websocketClient_;
-    std::unique_ptr<std::thread> mainThread_;
-    OnceFlag stoppedFlag_;
-
     const QString host_;
 
     /// Short name of the service (e.g. "7TV" or "BTTV")