[pear/Net_Sieve] a359ca: Fix PHP8.1 deprecation warning if $user=null

[email protected] ("Aleksander Machniak via pear-cvs") Thu, 26 Aug 2021 23:10:41 -0700

Newsgroups	php.pear.cvs
Message-ID	<pear/Net_Sieve/push/refs/heads/master/[email protected]>

  Branch: refs/heads/master
  Home:   https://github.com/pear/Net_Sieve
  Commit: a359cab56f510a32b7935fdc443c302bbc850892
      https://github.com/pear/Net_Sieve/commit/a359cab56f510a32b7935fdc443c302bbc850892
  Author: Aleksander Machniak <[email protected]>
  Date:   2021-08-27 (Fri, 27 Aug 2021)

  Changed paths:
    M Sieve.php

  Log Message:
  -----------
  Fix PHP8.1 deprecation warning if $user=null