Add an upstream-submitted (but not accepted) patch in order to allow
crda to be built with python2 as well as python3.
This drops m2crypto usage (python2-only) in favour of pycrypto which can
be built against both major versions.
Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
