cmd/gerritbot: reword message for when a Gerrit message is posted
cmd/gerritbot: reword message for when a Gerrit message is posted

Update golang/go#18517

Change-Id: Iccb7b5c61d8fc161b877d0a39f4ee1c523a4cd75
Reviewed-on: https://go-review.googlesource.com/93356
Reviewed-by: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>

golang/build,golang/build,golang/build,golang/build