remove optional user fields backend

##################################
//remove optional user fields backend
##################################

add_filter( 'user_contactmethods', 'newfields' );
function newfields( $user_contact ) {
    unset($user_contact['facebook']);
    unset($user_contact['twitter']);
     unset($user_contact['linkedin']);
    unset($user_contact['instagram']);
     unset($user_contact['youtube']);
    unset($user_contact['phone']);
      unset($user_contact['myspace']);
          unset($user_contact['pinterest']);
    unset($user_contact['soundcloud']);
    unset($user_contact['tumblr']);
    unset($user_contact['wikipedia']);
    return $user_contact;
 }