removing static prompt collapse/expand UI control

apps/openassessment/templates/openassessmentblock/oa_base.html

@@ -55,12 +55,6 @@
                     <div class="openassessment__prompt__copy ui-toggle-visibility__content">
                         <p>{{ question }}</p>
                     </div>
-
-                    <ul class="list list--controls">
-                        <li class="list--controls__item">
-                            <a href="" class="action action--toggle ui-toggle-visibility__control">Collapse/Expand This</a>
-                        </li>
-                    </ul>
                 </article>
             </div>