Minor issue errors with missing AES.MODE_CCM with PyCrypto older than 2.6.1

[clach04]

Not an issue with pycryptodome v3.0 and later (e.g. pycryptodome-3.14.1 is fine)

I.e. https://github.com/Legrandin/pycryptodome/commit/57104488faa9fc386ea1aee249bafb6e2a529a57 is required