CC-2873: Soundcloud plugin doesn't log any error when there is an error

with soundcloud uploading through api controller

- Changed constant names
- added -1 constant

airtime_mvc/application/configs/constants.php

@@ -37,5 +37,6 @@ define('UI_PLAYLIST_SESSNAME', 'PLAYLIST');
 
 
 // Soundcloud contants
-define('SC_PROGRESS', -2);
-define('SC_ERROR', -2);
+define('SOUNDCLOUD_NULL', -1);
+define('SOUNDCLOUD_PROGRESS', -2);
+define('SOUNDCLOUD_ERROR', -3);