slapos_upgrader: it seems activity is also triggered on already migrated instance

master/bt5/slapos_upgrader/SkinTemplateItem/portal_skins/slapos_upgrader/Instance_activateMigrationToRemoteProject.py

@@ -12,9 +12,13 @@ connection_xml = instance.getConnectionXml()
 remote_node = portal.restrictedTraverse(remote_node_relative_url)
 remote_partition = instance.getAggregateValue()
 
-assert instance_virtual_master_relative_url == remote_node.getFollowUp()
-assert instance_virtual_master_relative_url != remote_node.getDestinationProject()
-assert remote_partition.getFollowUp() == remote_node.getDestinationProject()
+try:
+  assert instance_virtual_master_relative_url == remote_node.getFollowUp()
+  assert instance_virtual_master_relative_url != remote_node.getDestinationProject()
+  assert remote_partition.getFollowUp() == remote_node.getDestinationProject()
+except AssertionError:
+  # Something wrong here, maybe the instance was already migrated
+  return
 
 #########################################################
 # Move current instance to the remote node