gstlal_excesspower_trigvis: Use contenthandler

gstlal-burst/bin/gstlal_excesspower_trigvis

@@ -44,6 +44,8 @@ import itertools
 from glue.ligolw import utils
 from glue.ligolw import lsctables
 from glue.ligolw import table
+from glue.ligolw import ligolw
+lsctables.use_in(ligolw.LIGOLWContentHandler)
 from glue import segments
 from glue.lal import LIGOTimeGPS
 from glue.lal import Cache