Focus on input when showing 2FA form in login modal.

app/assets/javascripts/discourse/controllers/login.js.es6

@@ -105,6 +105,8 @@ export default Ember.Controller.extend(ModalFunctionality, {
 
             $("#credentials").hide();
             $("#second-factor").show();
+            $("#second-factor input").focus();
+
             return;
           } else if (result.reason === 'not_activated') {
             self.send('showNotActivated', {

app/assets/javascripts/discourse/templates/components/second-factor-form.hbs

@@ -4,9 +4,6 @@
 
   <table>
     <tr>
-      <td>
-        <label for='login-second-factor'>{{i18n 'login.second_factor_label'}}&nbsp;</label>
-      </td>
       <td>
         {{yield}}
       </td>