Enhance - Convert more messages (#2646)

convert more messages to messages class
skipped dashboard messages due to them relying on $_SESSION['message']
to know if there has already been a change

app/dialplan/dialplan_xml.php

@@ -104,7 +104,7 @@
 			$cache->delete("dialplan:".$dialplan_context);
 
 		//save the message to a session variable
-			$_SESSION['message'] = $text['message-update'];
+			messages::add($text['message-update']);
 
 		//redirect the user
 			header("Location: dialplan_edit.php?id=".$dialplan_uuid."&".((strlen($app_uuid) > 0) ? "?app_uuid=".$app_uuid : null));