[dovecot/core] d49715: pop3c: Add no pipelining pop3c feature

[GitHub]

  Branch: refs/heads/master-2.2
  Home:   https://github.com/dovecot/core
  Commit: d4971519118499b56c47a0a78ce199237e858dd8
      https://github.com/dovecot/core/commit/d4971519118499b56c47a0a78ce199237e858dd8
  Author: Aki Tuomi <aki.tuomi at dovecot.fi>
  Date:   2017-02-20 (Mon, 20 Feb 2017)

  Changed paths:
    M src/lib-storage/index/pop3c/pop3c-client.c
    M src/lib-storage/index/pop3c/pop3c-client.h
    M src/lib-storage/index/pop3c/pop3c-mail.c
    M src/lib-storage/index/pop3c/pop3c-settings.c
    M src/lib-storage/index/pop3c/pop3c-settings.h
    M src/lib-storage/index/pop3c/pop3c-storage.c

  Log Message:
  -----------
  pop3c: Add no pipelining pop3c feature

This should help with certain broken pop3c
servers that advertise that they support pipelining
but they really don't.