[dovecot/core] 06c559: lazy-expunge: Fix error handling for GUID lookups

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/dovecot/core
  Commit: 06c55920c133602d6347f574b4149a083935cca8
      https://github.com/dovecot/core/commit/06c55920c133602d6347f574b4149a083935cca8
  Author: Timo Sirainen <timo.sirainen at dovecot.fi>
  Date:   2017-02-22 (Wed, 22 Feb 2017)

  Changed paths:
    M src/plugins/lazy-expunge/lazy-expunge-plugin.c

  Log Message:
  -----------
  lazy-expunge: Fix error handling for GUID lookups

If the mail is already expunged, the error should be ignored.
In other situations the original error string should be preserved as
part of the logged error message.