[dovecot/core] 16161d: lib-fts: Add missing include

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/dovecot/core
  Commit: 16161da6716cb679e315d59146fa3d5a93b4f031
      https://github.com/dovecot/core/commit/16161da6716cb679e315d59146fa3d5a93b4f031
  Author: Aki Tuomi <aki.tuomi at dovecot.fi>
  Date:   2016-08-23 (Tue, 23 Aug 2016)

  Changed paths:
    M src/lib-fts/fts-filter-common.c

  Log Message:
  -----------
  lib-fts: Add missing include