git-p4: importing labels should cope with missing owner
git-p4: importing labels should cope with missing owner

In p4, the Owner field is optional. If it is missing,
construct something sensible rather than crashing.

Signed-off-by: Luke Diamand <6b3799be4300e44489a08090123f3842e6419da5@diamand.org>
Acked-by: Pete Wyckoff <1a91d62f7ca67399625a4368a6ab5d4a3baa6073@padd.com>
Signed-off-by: Junio C Hamano <a6723cc3f76163bf7adb636a73ac3b0ceb3e6b9b@pobox.com>

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