[TEST] fix test_login_logout
[TEST] fix test_login_logout

- The tests worked locally, on the WM CI but not on Travis. It seems that
the login is in progress while expected as completed. Added this case.

Bug: T222508
Change-Id: I1dd500880ce6f2f995953c815fb24f0989e30b11

PersianWikipedia/pywikibot-core,wikimedia/pywikibot-core,wikimedia/pywikibot-core