Fix bug: errors occur when instructor approve anonymous suggested topics.
Fix bug: errors occur when instructor approve anonymous suggested topics.

urmilparikh95/expertiza,kira0992/expertiza,urmilparikh95/expertiza,kira0992/expertiza,expertiza/expertiza,expertiza/expertiza,urmilparikh95/expertiza,kira0992/expertiza,kira0992/expertiza,expertiza/expertiza,expertiza/expertiza,urmilparikh95/expertiza