MOBILE-2795 assign: Fix fetching grades when assingment has no submissions
MOBILE-2795 assign: Fix fetching grades when assingment has no submissions

dpalou/moodlemobile2,FMCorz/moodlemobile2,reskit/moodlemobile,saman222/moodlemobile2,moodlehq/moodlemobile2,saman222/moodlemobile2,reskit/moodlemobile,reskit/moodlemobile,FMCorz/moodlemobile2,saman222/moodlemobile2,moodlehq/moodlemobile2,reskit/moodlemobile,dpalou/moodlemobile2,moodlehq/moodlemobile2,moodlehq/moodlemobile2,dpalou/moodlemobile2,saman222/moodlemobile2,reskit/moodlemobile,reskit/moodlemobile,saman222/moodlemobile2,moodlehq/moodlemobile2,moodlehq/moodlemobile2