[dovecot/core] 848018: dict: Avoid potentially using 100% CPU

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/dovecot/core
  Commit: 84801834c5ae4e9b1fe6679e4080986601ccd78c
      https://github.com/dovecot/core/commit/84801834c5ae4e9b1fe6679e4080986601ccd78c
  Author: Timo Sirainen <timo.sirainen at dovecot.fi>
  Date:   2016-06-13 (Mon, 13 Jun 2016)

  Changed paths:
    M src/dict/dict-connection.c

  Log Message:
  -----------
  dict: Avoid potentially using 100% CPU

Continuing 65c570f18 fix.