Fixed legal aria-label to be a valid label

AC-596

fixed aria-label to just say legal

translate legal label

cms/templates/widgets/footer.html

@@ -29,7 +29,7 @@ from django.core.urlresolvers import reverse
       % endif
     </div>
 
-    <div class="footer-content-secondary" aria-label="{_('Legal')}">
+    <div class="footer-content-secondary" aria-label="${_("Legal")}">
       <div class="footer-about-copyright">
         ## Site operators: Please do not remove this paragraph! This attributes back to edX and makes your acknowledgement of edX's trademarks clear.
         <p>