Hopefully fix a bug that broke wiki update
    
    We can only actually find out if this fixes the bug in another
    six months, such is the nature of this tool :/ The last two
    releases or so - I think since python-bugzilla 7fd3328b - the
    wiki update has failed at this line:
    
                bugid = [bug for bug in bugs if (hasattr(bug, 'alias') and alias in bug.alias)][0].id
    
    for the next-next release (where the tracker bugs have just
    been created, i.e. where update_nextnext was used and the list
    of bugs consists of the results of `bzapi.createbug()` calls).
    I think it's failing because these `Bug` instances don't have
    the 'alias' attribute, as `createbug` only returns pretty
    simple instances:
    
            return Bug(self, bug_id=rawbug["id"],
                       autorefresh=self.bug_autorefresh)
    
    We could fix this by turning autorefresh back on while we produce
    these Bug instances, but that produces annoying log messages, so
    instead, let's just re-generate the list by calling get_trackers
    after we're done creating the trackers, since that call makes
    sure we get the aliases.
    
    Signed-off-by: Adam Williamson <awilliam@redhat.com>