Message 320857 - Python tracker

My PR 8043 fix the Python 3.7 regression: allow again to call Py_Main() after Py_Initialize().

Nick: if you want to raise an error on that case, I would prefer to see a deprecation warning emitted in version N before raising an error in version N+1.

Technically, it seems possible to allow calling Py_Main() after Py_Initialize(). It's "just" a matter of fixing Py_Main() to apply properly the new configuration.