Originally reported by rrusso @ MDL-38851

Grade export plain text file:
Did you remember to call setType() for 'iprestriction'? Defaulting to PARAM_RAW cleaning.
line 1303 of /lib/formslib.php: call to debugging()
line 281 of /lib/formslib.php: call to moodleform->detectMissingSetType()
line 202 of /lib/formslib.php: call to moodleform->_process_submission()
line 43 of /grade/export/txt/index.php: call to moodleform->moodleform()

Ciao