gstlal_inspiral_pipe: put background prior back to 1 count

(cherry picked from commit b7cca460)

gstlal-inspiral/bin/gstlal_inspiral_pipe

@@ -511,7 +511,7 @@ def rank_and_merge(dag, createPriorDistStatsJob, calcRankPDFsJob, calcRankPDFsWi
 		# the time being.
 		priornode = dagparts.DAGNode(createPriorDistStatsJob, dag,
 				parent_nodes = [one_ifo_svd_nodes[n]] + mass_model_add_node or [],
-				opts = {"instrument":instrument_set, "background-prior":10000, "min-instruments":options.min_instruments, "df": "bandwidth", "coincidence-threshold":options.coincidence_threshold},
+				opts = {"instrument":instrument_set, "background-prior":1, "min-instruments":options.min_instruments, "df": "bandwidth", "coincidence-threshold":options.coincidence_threshold},
 				input_files = {"svd-file":one_ifo_svd_nodes[n].output_files["write-svd"], "mass-model-file":mass_model_file, "dtdphi-file":svd_to_dtdphi_map[n], "psd-xml": ref_psd},
 				output_files = {"write-likelihood":dagparts.T050017_filename(instruments, '%04d_CREATE_PRIOR_DIST_STATS' % (n,), boundary_seg, '.xml.gz', path = createPriorDistStatsJob.output_path)}
 			)