[bugfix] Remove test_bluwiki test_T235768_failure
[bugfix] Remove test_bluwiki test_T235768_failure

Neither http://bluwiki.com nor http://bluewiki.com exits
(any longer). Remove this test.

Change-Id: I99253b791482defdb78ee8d8303a9027feb35f8f

wikimedia/pywikibot-core,wikimedia/pywikibot-core