Philippe Pepiot <philippe.pepiot@logilab.fr> [Tue, 21 May 2019 10:18:38 +0200] rev 12619
[crypto] Encode unicode strings in _cypherer()
pycrypto accept both bytes or string but pycryptodome, which will be introduced
in next changeset, doesn't accept this.
For backward compatibility, encode unicode strings in _cypherer()