Adds an admin notice alerting the user to check for confirmation request email
after email address change.

function new_user_email_admin_notice() {
	global $pagenow;

	if ( 'profile.php' === $pagenow && isset( $_GET['updated'] ) ) {
		$email = get_user_meta( get_current_user_id(), '_new_email', true );
		if ( $email ) {
			/* translators: %s: New email address. */
			echo '
' . sprintf( __( 'Your email address has not been updated yet. Please check your inbox at %s for a confirmation email.' ), '' . esc_html( $email['newemail'] ) . '' ) . '
';
		}
	}
}