merge: give a bit prettier merge message to "merge branch~$n"
merge: give a bit prettier merge message to "merge branch~$n"

This hacks the input to fmt-merge-msg to make the message for
merging early part of a branch a little easier to read.

Signed-off-by: Junio C Hamano <dc50d1021234060e53ec42a77d526afa2fe07479@cox.net>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git