Avoid use of "$_SERVER['REQUEST_URI']"

Use the routing library to build proper URIs instead of relying on the
"REQUEST_URI" server variable which can be manipulated and might return
bogus URIs.

Signed-off-by: Lukas Fleischer <archlinux@cryptocrack.de>

web/template/pkg_comment_form.php

@@ -1,6 +1,6 @@
 <div id="generic-form" class="box">
 	<h2><?= __("Add Comment"); ?></h2>
-	<form action="<?= $_SERVER['REQUEST_URI'] ?>" method="post">
+	<form action="<?= get_pkg_uri($row['Name']) ?>" method="post">
 		<fieldset>
 <?php
 if (isset($_REQUEST['comment']) && check_token()) {