Merge pull request #1878 from MITx/fix/btalbot/studio-graceperiod

Correcting placeholder text for grace period field in course settings

cms/templates/settings_graders.html

@@ -97,7 +97,7 @@ from contentstore import utils
           <ol class="list-input">
             <li class="field text" id="field-course-grading-graceperiod">
               <label for="course-grading-graceperiod">Grace Period on Deadline:</label>
-              <input type="text" class="short time" id="course-grading-graceperiod" value="0:00" placeholder="e.g. 10 minutes">
+              <input type="text" class="short time" id="course-grading-graceperiod" value="0:00" placeholder="HH:MM" autocomplete="off" />
               <span class="tip tip-inline">Leeway on due dates</span>
             </li>
           </ol>