[dovecot/core] 1d54f0: quota-clone: Fix compile warning

[GitHub]

  Branch: refs/heads/master-2.2
  Home:   https://github.com/dovecot/core
  Commit: 1d54f0db739bb2b8ecdf406cf1ee410e939becdc
      https://github.com/dovecot/core/commit/1d54f0db739bb2b8ecdf406cf1ee410e939becdc
  Author: Timo Sirainen <timo.sirainen at dovecot.fi>
  Date:   2017-06-14 (Wed, 14 Jun 2017)

  Changed paths:
    M src/plugins/quota-clone/quota-clone-plugin.c

  Log Message:
  -----------
  quota-clone: Fix compile warning