segments.py: add O3b GPS times to GWOSC URL

gstlal/python/segments.py

@@ -412,6 +412,8 @@ def _gwosc_segment_url(start, end, flag):
 		query_url = f"{urlbase}/O2_16KHZ_R1"
 	elif start in segments.segment(1238166018, 1253977218):
 		query_url = f"{urlbase}/O3a_16KHZ_R1"
+	elif start in segments.segment(1256655618, 1269363618):
+		query_url = f"{urlbase}/O3b_16KHZ_R1"
 	else:
 		raise ValueError("GPS times requested not in GWOSC")