gitweb: Fix @git_base_url_list usage

As it is now, that array was never used because the customurl accessor was
broken and ''unless @url_list'' never happenned.

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

gitweb/gitweb.perl

@@ -752,7 +752,7 @@ sub git_get_project_description {
 sub git_get_project_url_list {
 	my $path = shift;
 
-	open my $fd, "$projectroot/$path/cloneurl" or return undef;
+	open my $fd, "$projectroot/$path/cloneurl" or return;
 	my @git_project_url_list = map { chomp; $_ } <$fd>;
 	close $fd;