Translate connect header to spanish

Support team suggests translation of one of the footer title
to spanish.In this PR, hooks are added around that title so
that it can be translated.

themes/edx.org/lms/templates/footer.html

@@ -75,7 +75,7 @@
                  <div class="col-xl-4 col-lg-4 col-md-4 col-sm-12 col-xs-12 column-2-1 third-div-border column-styles">
                       <div class="row full-height">
                         <div class="col-lg-12 col-md-12 col-sm-10 full-height column-2-2 column-styles">
-                              <h2 class="heading">Connect</h2>
+                              <h2 class="heading">${_(u"Connect")}</h2>
                               <ul class="list-unstyled clear-margins  ">
                                 % for link in footer["connect_links"]:
                                 <li>