Fixed feedback form page accessibility issue

- The form used a fieldset tag instead of a form tag

src/app/info/feedback/feedback-form/feedback-form.component.html

@@ -3,7 +3,7 @@
     <form class="primary" [formGroup]="feedbackForm" (ngSubmit)="createFeedback()">
       <h1>{{ 'info.feedback.head' | translate }}</h1>
       <p>{{ 'info.feedback.info' | translate }}</p>
-      <fieldset class="col p-0">
+      <form class="col p-0">
         <div class="row">
           <div class="control-group col-sm-12">
             <label class="control-label" for="email">{{ 'info.feedback.email-label' | translate }}&nbsp;</label>
@@ -39,7 +39,7 @@ <h1>{{ 'info.feedback.head' | translate }}</h1>
             <button [disabled]="!feedbackForm.valid" class="btn btn-primary" name="submit" type="submit">{{ 'info.feedback.send' | translate }}</button>
           </div>
         </div>
-      </fieldset>
+      </form>
     </form>
   </div>
 </div>