Qt ConfirmTxDialog: disconnect timer when closing dialog

fixes https://github.com/spesmilo/electrum/issues/6791

electrum/gui/qt/confirm_tx_dialog.py

@@ -67,6 +67,9 @@ class TxEditor:
             self.update()
             self.needs_update = False
 
+    def stop_editor_updates(self):
+        self.main_window.gui_object.timer.timeout.disconnect(self.timer_actions)
+
     def fee_slider_callback(self, dyn, pos, fee_rate):
         if dyn:
             if self.config.use_mempool_fees():
@@ -193,6 +196,7 @@ class ConfirmTxDialog(TxEditor, WindowModalDialog):
     def run(self):
         cancelled = not self.exec_()
         password = self.pw.text() or None
+        self.stop_editor_updates()
         self.deleteLater()  # see #3956
         return cancelled, self.is_send, password, self.tx
 

electrum/gui/qt/transaction_dialog.py

@@ -989,6 +989,7 @@ class PreviewTxDialog(BaseTxDialog, TxEditor):
             return
         assert self.tx
         self.finalized = True
+        self.stop_editor_updates()
         self.tx.set_rbf(self.rbf_cb.isChecked())
         locktime = self.locktime_e.get_locktime()
         if locktime is not None: