gitweb: fix uninitialized variable warning.
gitweb: fix uninitialized variable warning.

Perl spit out a varning when "blob" or "blob_plain" actions were
used without a $hash parameter.

Signed-off-by: Martin Waitz <7b58d40291ca68e315b464e082026bd30087ffb3@admingilde.org>
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