Fix error on py2 when import numpy

[opacam]

Also:

• make use of python3 super() for numpy recipe

Closes: #1988

[AndreMiras]

LGTM, thanks
Even though it often hurts me to see time/effort spent on Python2 specific. That actually deserves a won't fix to incentive users to move to target Python3 as well

[opacam]

Aaa.. you are right @AndreMiras, people should move to python3, but we still have python2 in here, so I have the feeling that we should give a solution, or we will fill p4a issues about the same error, anyway feel free to merge this yourself or close it I give this to your judgement 😉