Squish: Wait a second in checkNavigator()

Change-Id: I45bad30e28f7374ae10d5b0155e08d8297f44448
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

tests/system/suite_general/tst_session_handling/test.py

@@ -121,6 +121,7 @@ def checkWelcomePage(sessionName, isCurrent=False):
 
 def checkNavigator(expectedRows, message):
     navigatorModel = waitForObject(":Qt Creator_Utils::NavigationTreeView").model()
+    waitFor("expectedRows == len(__iterateChildren__(navigatorModel, QModelIndex()))", 1000)
     test.compare(expectedRows, len(__iterateChildren__(navigatorModel, QModelIndex())), message)
 
 def checkOpenDocuments(expectedRows, message):