Remove duplicate 'Hi' menu item from toolbar on mobile.

See #3472.

wp-content/mu-plugins/openlab-toolbar.php

@@ -481,7 +481,7 @@ public function change_howdy_to_hi( $wp_admin_bar ) {
 				'id'    => 'my-account',
 				'title' => sprintf( 'Hi, %s', $bp->loggedin_user->userdata->display_name ),
 				'meta'  => array(
-					'class' => 'user-display-name',
+					'class' => 'user-display-name hidden-xs',
 				),
 			)
 		);