Fix missing legend in user login

Author: chmst

components/com_users/tmpl/login/default_login.php

@@ -53,7 +53,7 @@
 
     <form action="<?php echo Route::_('index.php?task=user.login'); ?>" method="post" id="com-users-login__form" class="com-users-login__form form-validate form-horizontal well">
 
-        <fieldset>
+        <fieldset role="group" aria-label="<?php echo Text::_('COM_USERS_LOGIN_CREDENTIALS'); ?>">
             <?php echo $this->form->renderFieldset('credentials', ['class' => 'com-users-login__input']); ?>
 
             <?php if (PluginHelper::isEnabled('system', 'remember')) : ?>

language/en-GB/com_users.ini

@@ -33,6 +33,7 @@ COM_USERS_FIELD_RESET_PASSWORD2_LABEL="Confirm Password"
 COM_USERS_FRONTEND_LOGOUT_SUCCESS="You have been logged out."
 COM_USERS_INVALID_EMAIL="Invalid email address"
 COM_USERS_LBL_SELECT_INSTRUCTIONS="Please select how you would like to verify your login to this site."
+COM_USERS_LOGIN_CREDENTIALS="Login with user credentials"
 COM_USERS_LOGIN_DEFAULT_LABEL="User Login"
 COM_USERS_LOGIN_REGISTER="Don't have an account?"
 COM_USERS_LOGIN_REMEMBER_ME="Remember me"