Fix poster moment tag

sheetsync/sheetsync/streamlog.py

@@ -162,12 +162,13 @@ class StreamLogEventsMiddleware(Middleware):
 		output["sheet_name"] = row["tab"]["name"] if row["tab"] else "unknown"
 
 		# Implicit tags
-		output['tags'] = [
+		implicit_tags = [
 			output['category'],
 			output["sheet_name"],
-		] + output['tags']
+		]
 		if output["poster_moment"]:
-			output['tags'] += 'Poster Moment'
+			implicit_tags.append('Poster Moment')
+		output['tags'] = implicit_tags + output['tags']
 
 		# Convey parent info
 		if row["depth"] > 0: