[API] Generator: Add watcher.delete_watch to endpoint specific 404

Author: picandocodigo

elasticsearch-api/utils/thor/generator/endpoint_specifics.rb

@@ -36,6 +36,7 @@ module EndpointSpecifics
         snapshot.delete_repository
         snapshot.delete
         update
+        watcher.delete_watch
       ].freeze
 
       # Endpoints that need params[:h] listified