BUG If user is logged out getHtmlEditorConfigForCMS() gets called on non object

This can happen if the auto-logout feature logs a user out and the user then tries to open another admin or
do an pjax call.
Merge pull request #3299 from stojg/pull/if-user-logged-out-causes-500-error

BUG If user is logged out getHtmlEditorConfigForCMS() gets called on non object