Allow task assignees to upload subtitles.
Allow task assignees to upload subtitles.

For https://unisubs.sifterapp.com/projects/12298/issues/557490/comments

wevoice/wesub,norayr/unisubs,wevoice/wesub,pculture/unisubs,ReachingOut/unisubs,wevoice/wesub,ofer43211/unisubs,ofer43211/unisubs,ujdhesa/unisubs,eloquence/unisubs,eloquence/unisubs,eloquence/unisubs,ujdhesa/unisubs,ujdhesa/unisubs,ReachingOut/unisubs,pculture/unisubs,pculture/unisubs,wevoice/wesub,norayr/unisubs,ReachingOut/unisubs,ofer43211/unisubs,norayr/unisubs,eloquence/unisubs,ReachingOut/unisubs,pculture/unisubs,ofer43211/unisubs,ujdhesa/unisubs,norayr/unisubs