sourceRouteThread: log unhandled exceptions

Change-Id: I23eaf7a41c8decaea64a392d58ef6ba31f24d795
Signed-off-by: Antoni S. Puimedon <asegurap@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/22670
Reviewed-by: Dan Kenigsberg <danken@redhat.com>
Tested-by: Dan Kenigsberg <danken@redhat.com>