Use offline and AlwaysTrust for S/MIME draft enc

* src/cryptcontroller.cpp (CryptController::do_crypto):
Check for draft encryption and then enable forced behavior.

When encrypting a draft it needs to be quick since it can happen
on Autosave at any point so we do not want to do CRL checks in that
case. And might also ignore other errors related to the certificate.

• GnuPG-Bug-Id: T6827