cephadmunit: Python3 fix: signal.SIGHUP is no longer an int.
cephadmunit: Python3 fix: signal.SIGHUP is no longer an int.

py2: `str(signal.SIGHUP) == "1"`
py3: `str(signal.SIGHUP) == "signal.SIGHUP"`

Fixes: https://tracker.ceph.com/issues/45297

Signed-off-by: Sebastian Wagner <fb2a023681e561026fe4622db20ef25b3a9b9384@suse.com>

dmick/teuthology,ktdreyer/teuthology,SUSE/teuthology,ceph/teuthology,dmick/teuthology,SUSE/teuthology,SUSE/teuthology,ktdreyer/teuthology,dmick/teuthology,ceph/teuthology