tests: avoid periodic updates to interfere with a test

This one: test_415_template_vm_started
It tests if template start/stop triggered the updates available state
update. Suppress periodic update of the same.

qubesmanager/qube_manager.py

@@ -516,9 +516,9 @@ def __init__(self, qt_app, qubes_app, dispatcher, parent=None):
         self.progress = None
 
         # Check Updates Timer
-        timer = QtCore.QTimer(self)
-        timer.timeout.connect(self.check_updates)
-        timer.start(1000 * 30)  # 30s
+        self.timer = QtCore.QTimer(self)
+        self.timer.timeout.connect(self.check_updates)
+        self.timer.start(1000 * 30)  # 30s
         self.check_updates()
 
     def keyPressEvent(self, event):  # pylint: disable=invalid-name

qubesmanager/tests/test_qube_manager.py

@@ -1146,6 +1146,7 @@ def test_415_template_vm_started(self):
             if target_vm_name:
                 break
 
+        self.dialog.timer.stop()
         for i in range(self.dialog.table.rowCount()):
             self._get_table_item(i, "State").update_vm_state =\
                 unittest.mock.Mock()