[dovecot/core] ec3eb5: pop3c: Add no pipelining pop3c feature

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/dovecot/core
  Commit: ec3eb53293a282b409fe128153038522c294dda3
      https://github.com/dovecot/core/commit/ec3eb53293a282b409fe128153038522c294dda3
  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.