Update email in Contact Us page

pages/contact_us.vue

@@ -5,7 +5,7 @@
     <br />
     <p class="text-justify">
       To send any comment, feedback or suggestion please write an email to
-      <a href="mailto:chembl-help@ebi.ac.uk">chembl-help@ebi.ac.uk</a>.
+      <a href="mailto:help@gateway.eubopen.org">help@gateway.eubopen.org</a>.
     </p>
   </div>
 </template>