removes unnecessary js_block from form_question

test plan:
* regression testing of quizzes (form_question)

Change-Id: Id492e23bc414d53370821c87e521552495523b8a
Reviewed-on: https://gerrit.instructure.com/29134
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Jon Jensen <jon@instructure.com>
QA-Review: Myller de Araujo <myller@instructure.com>
Product-Review: Landon Wilkins <lwilkins@instructure.com>