Update page feedback widget to ignore empty feedback

lib/page-feedback.php

@@ -5,7 +5,7 @@
 $contact = "devel@lists.sucs.org";
 
 if ($session->loggedin) {
-    if ($_REQUEST["action"] == "feedback") {
+    if ($_REQUEST["action"] == "feedback" && $_REQUEST["feedback"] != "") {
         $feedback = $_REQUEST["feedback"];
 
         $msgbody = "{$session->username} had this to say about the page {$_SERVER['REQUEST_URI']}:\r\n\r\n";