[dovecot/core] 201ce6: lib-mail: Fix duplicate HEADER_FILTER_ADD_MISSING_...

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/dovecot/core
  Commit: 201ce62e1dc315e5dd5e59c24660ed0946343bbb
      https://github.com/dovecot/core/commit/201ce62e1dc315e5dd5e59c24660ed0946343bbb
  Author: Timo Sirainen <timo.sirainen at dovecot.fi>
  Date:   2017-02-15 (Wed, 15 Feb 2017)

  Changed paths:
    M src/lib-mail/istream-header-filter.c
    M src/lib-mail/test-istream-header-filter.c

  Log Message:
  -----------
  lib-mail: Fix duplicate HEADER_FILTER_ADD_MISSING_EOH callback call

If headers weren't modified, the second reading of the istream shouldn't
call any callbacks.