Bug fix:  Add CRF value as a string
Bug fix:  Add CRF value as a string

While adding support for using quality settings instead of constant bitrate, found this bug.  Without it, the _spawn() command errors out with:
'sequence item 9: expected string or Unicode, int found'
Collisionc/sickbeard_mp4_automator,Filechaser/sickbeard_mp4_automator,Collisionc/sickbeard_mp4_automator,phtagn/sickbeard_mp4_automator,Filechaser/sickbeard_mp4_automator,phtagn/sickbeard_mp4_automator