labels plugin qt: only update corresponding window; disconnect signal

electrum/gui/qt/main_window.py

@@ -794,7 +794,11 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, PrintError):
         if self.wallet.up_to_date or not self.network or not self.network.is_connected():
             self.update_tabs()
 
-    def update_tabs(self):
+    def update_tabs(self, wallet=None):
+        if wallet is None:
+            wallet = self.wallet
+        if wallet != self.wallet:
+            return
         self.history_list.update()
         self.request_list.update()
         self.address_list.update()

electrum/plugins/labels/qt.py

@@ -75,4 +75,8 @@ class Plugin(LabelsPlugin):
 
     @hook
     def on_close_window(self, window):
+        try:
+            self.obj.labels_changed_signal.disconnect(window.update_tabs)
+        except TypeError:
+            pass  # 'method' object is not connected
         self.stop_wallet(window.wallet)