[dovecot/core] a9b8af: lib-mail: Fix include guards for istream-nonuls.h

[GitHub]

  Branch: refs/heads/master-2.2
  Home:   https://github.com/dovecot/core
  Commit: a9b8af221b2337cbca1d68773502db59f8752129
      https://github.com/dovecot/core/commit/a9b8af221b2337cbca1d68773502db59f8752129
  Author: Sergey Kitov <sergey.kitov at open-xchange.com>
  Date:   2018-04-17 (Tue, 17 Apr 2018)

  Changed paths:
    M src/lib-mail/istream-nonuls.h

  Log Message:
  -----------
  lib-mail: Fix include guards for istream-nonuls.h