Remove deprecated constants.

plugins/FeedsNodeProcessor.inc

@@ -6,12 +6,6 @@
  * Class definition of FeedsNodeProcessor.
  */
 
-// Deprecated. Use FEEDS_SKIPE_EXISTING, FEEDS_REPLACE_EXISTNG,
-// FEEDS_UPDATE_EXISTING instead.
-define('FEEDS_NODE_SKIP_EXISTING', 0);
-define('FEEDS_NODE_REPLACE_EXISTING', 1);
-define('FEEDS_NODE_UPDATE_EXISTING', 2);
-
 // "Use the present default format"
 define('FEEDS_NODE_DEFAULT_FORMAT', -1);