Python3.6: Compatibility, only make check when the backport was done.
Python3.6: Compatibility, only make check when the backport was done.

* This check of 3.7 was backported to 3.6.4 only, and therefore this
  could cause some test failures on older 3.6 versions now.

kayhayen/Nuitka,kayhayen/Nuitka,kayhayen/Nuitka,kayhayen/Nuitka