When admin tries to hide (disable) tinymce plugin there is an error

Notice: Undefined variable: delete in /home/marina/repositories/master/moodle/lib/editor/tinymce/subplugins.php on line 33 Call Stack: 0.0003 662600 1. {main}() /home/marina/repositories/master/moodle/lib/editor/tinymce/subplugins.php:0 

Also I tried to hide moodlemedia plugin, but did not remove 'moodlemedia' from the layout and the button was displayed and continued working. It might be an issue with pdw plugin (MDL-37565) that adds button automatically