Check for PGP/Inline inside of S/MIME mails
* src/mapihelp.cpp (change_message_class_ipm_note_smime_multipartsigned): Check for PGP/Inline if S/MIME is disabled.
This is a hack to handle the case where some crypto gateway
might wrap a PGP Inline message inside an S/MIME message.
- GnuPG-Bug-Id: T4115