inspiral_lr.py: add a single detector penalty of -5 for the log LR

gstlal-inspiral/python/stats/inspiral_lr.py

@@ -357,6 +357,12 @@ class LnSignalDensity(LnLRDensity):
 		except ValueError:
 			return NegInf
 
+		# FIXME NOTE
+		# Here we put in a penalty for single detector triggers.
+		# Motivated sort of by the coincidence probability.
+		if len(snrs) == 1:
+			lnP -= 5
+
 		# evaluate population model
 		lnP += self.population_model.lnP_template_signal(template_id, max(snrs.values()))