protocoldetector: Unify log messages

We stare at vdsm logs for hours, lets make it little nicer.

Change-Id: I4721ad5e383031e7e8184b4f364434d9401e96b9
Signed-off-by: Nir Soffer <nsoffer@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/34334
Reviewed-by: Piotr Kliczewski <piotr.kliczewski@gmail.com>
Reviewed-by: Dan Kenigsberg <danken@redhat.com>