Remove extraneous refund text

Bug: LMS-1603

lms/templates/dashboard.html

@@ -329,7 +329,6 @@
     <button class="close-modal">&#10005; <span class="sr">${_('Close Modal')}</span></button>
     <header>
       <h2 id="unenrollment-modal-title">${_('<span id="track-info"></span> {course_number}?  <span id="refund-info"></span>').format(course_number='<span id="unenroll_course_number"></span>')}<span class="sr">, ${_("modal open")}</span></h2>
-      refund
       <hr/>
     </header>
     <div id="unenroll_error" class="modal-form-error"></div>
@@ -341,4 +340,4 @@
       </div>
     </form>
   </div>
-</section>
+</section>