closes VICE-1529
flag=react_discussions_post
Test Plan:
-create a discussion with multiple due dates
-leave due, available, and until empty
-open multiple due date tray
-verify cells for displaying empty dates have
no date text
Change-Id: I2654052f8a8b36569bdfe5ffb4b836a3c2a65258
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/265920
Tested-by: Service Cloud Jenkins <svc.cloudjenkins@instructure.com>
Reviewed-by: Caleb Guanzon <cguanzon@instructure.com>
QA-Review: Caleb Guanzon <cguanzon@instructure.com>
Product-Review: Caleb Guanzon <cguanzon@instructure.com>
de6eca5923