[trojita] /: Merge changes from topic 'imap-wrong-bodystructure'

[Gerrit Code Review]

Git commit 272c3c0435f152695f896b0677918ad64cb6c8d3 by Gerrit Code Review, on behalf of Jan Kundrát.
Committed on 29/06/2018 at 00:49.
Pushed by gerrit into branch 'master'.

Merge changes from topic 'imap-wrong-bodystructure'

* changes:
  GUI: Special handling for parts whose MIME structure failed to parse
  IMAP: fall back to binary part rendering when BODYSTRUCTURE parsing fails


https://commits.kde.org/trojita/272c3c0435f152695f896b0677918ad64cb6c8d3