codereview: update name of the a+c tool

LGTM=rsc
R=rsc, minux
CC=golang-codereviews
https://golang.org/cl/105480043

lib/codereview/codereview.py

@@ -2057,7 +2057,7 @@ def needLGTM(cl):
 	isGobot = 'gobot' in rev or 'gobot@swtch.com' in rev or 'gobot@golang.org' in rev
 	
 	# A+C CLs generated by addca do not need LGTM
-	if cl.desc.startswith('A+C:') and 'Generated by addca.' in cl.desc and isGobot:
+	if cl.desc.startswith('A+C:') and 'Generated by a+c.' in cl.desc and isGobot:
 		return False
 	
 	# CLs modifying only go1.x.txt do not need LGTM