gitweb: Fix error in git_project_index subroutine

Instead of "$projectroot/$pr->{'path'}" to get the path to project
GIT_DIR, it was used "$projectroot/$project" which is valid only
for actions where project parameter is set, and 'project_index' is not
one of them.

Signed-off-by: Jakub Narebski <jnareb@gmail.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>

gitweb/gitweb.perl

@@ -2995,7 +2995,7 @@ sub git_project_index {
 
 	foreach my $pr (@projects) {
 		if (!exists $pr->{'owner'}) {
-			$pr->{'owner'} = get_file_owner("$projectroot/$project");
+			$pr->{'owner'} = get_file_owner("$projectroot/$pr->{'path'}");
 		}
 
 		my ($path, $owner) = ($pr->{'path'}, $pr->{'owner'});