gitweb: Require project for almost all actions

Require that project (repository) is given for all actions except
project_list, project_index and opml.

Signed-off-by: Jakub Narebski <jnareb@gmail.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>
diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
index 5f597f7..7fd2e19 100755
--- a/gitweb/gitweb.perl
+++ b/gitweb/gitweb.perl
@@ -352,6 +352,10 @@
 if (!defined($actions{$action})) {
 	die_error(undef, "Unknown action");
 }
+if ($action !~ m/^(opml|project_list|project_index)$/ &&
+    !$project) {
+	die_error(undef, "Project needed");
+}
 $actions{$action}->();
 exit;