Fix bug in feedback mode with showing examples when question has none
Fix bug in feedback mode with showing examples when question has none

kesiena115/threeflows,kesiena115/threeflows,mit-teaching-systems-lab/threeflows,kesiena115/threeflows,mit-teaching-systems-lab/threeflows,mit-teaching-systems-lab/threeflows,mit-teaching-systems-lab/threeflows