qt: Prevent thread/memory leak on exiting RPCConsole

src/qt/bitcoingui.cpp

@@ -527,6 +527,13 @@ void BitcoinGUI::setClientModel(ClientModel *clientModel)
             // Disable context menu on tray icon
             trayIconMenu->clear();
         }
+        // Propagate cleared model to child objects
+        rpcConsole->setClientModel(nullptr);
+#ifdef ENABLE_WALLET
+        walletFrame->setClientModel(nullptr);
+#endif // ENABLE_WALLET
+        unitDisplayControl->setOptionsModel(nullptr);
+        connectionsControl->setClientModel(nullptr);
     }
 }