Clean out the old jobs from all returners (if you have it)

def clean_old_jobs():
    '''
    Clean out the old jobs from all returners (if you have it)
    '''
    for returner_ in __opts__[CONFIG_KEY]:
        fstr = '{0}.clean_old_jobs'.format(returner_)
        if fstr in _mminion().returners:
            _mminion().returners[fstr]()