Fix git-tag -u
Fix git-tag -u

... which I broke when we introduced user.signingkey configuration.
There was no reason to add a new variable keyid to the script.

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