streamthinca: don't unlink coinc_event_map table

- doing so breaks gracedb uploads, and upon testing I have found that the unlink is not required to fix the memory leak

gstlal-inspiral/python/streamthinca.py

@@ -328,7 +328,6 @@ class StreamThinca(object):
 			map(real_coinc_event_map_table.append, coinc_event_map_table)
 		else:
 			background_coinc_sngls = []
-		coinc_event_map_table.unlink()
 
 		# record boundary
 		self.last_boundary = boundary