gitweb: Don't set owner if got empty value from projects.list

Prevent setting owner to an empty value if it is not specified in
projects.list file. Otherwise it stops retrieving information about the
owner from other files.

Signed-off-by: Kacper Kornet <draenog@pld-linux.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

gitweb/gitweb.perl

@@ -2997,9 +2997,11 @@ sub git_get_projects_list {
 			}
 			if (check_export_ok("$projectroot/$path")) {
 				my $pr = {
-					path => $path,
-					owner => to_utf8($owner),
+					path => $path
 				};
+				if ($owner) {
+					$pr->{'owner'} = to_utf8($owner);
+				}
 				push @list, $pr;
 			}
 		}