This update for enigmail fixes the following issues:
enigmail was updated to 2.1.5:
Security issue: unsigned MIME parts displayed as signed (bsc#1159973) * Ensure that upgrading GnuPG 2.0.x to 2.2.x upgrade converts keyring format * Make Enigmail Compatible with Protected-Headers spec, draft 2
enigmail 2.1.4:
Fixes for UI glitches * Option to 'Attach public key to messages' was not restored properly
enigmail 2.1.3:
fix a bug in the setup wizard that could lead the wizard to never complete scanning the inbox