Ignore type error messages as headline messages.

src/utils.js

@@ -129,12 +129,14 @@
             var $message = $(message),
                 from_jid = $message.attr('from');
             if ($message.attr('type') === 'headline' ||
-                    // Some servers (I'm looking at you Prosody) don't set the message
-                    // type to "headline" when sending server messages. For now we
-                    // check if an @ signal is included, and if not, we assume it's
-                    // a headline message.
-                    (typeof from_jid !== 'undefined' && from_jid.indexOf('@') === -1)
-                ) {
+                // Some servers (I'm looking at you Prosody) don't set the message
+                // type to "headline" when sending server messages. For now we
+                // check if an @ signal is included, and if not, we assume it's
+                // a headline message.
+                (   $message.attr('type') !== 'error' &&
+                    typeof from_jid !== 'undefined' &&
+                    from_jid.indexOf('@') === -1
+                )) {
                 return true;
             }
             return false;