s4:param: replace calls to deprecated Python methods

s4:param: replace calls to deprecated Python methods

Replace calls to (obsolete but still stable)
PyEval_CallObjectWithKeywords() with PyObject_Call()
by using trivial wrapper.

Signed-off-by: Dmitry Antipov <dantipov@cloudlinux.com>
Reviewed-by: Douglas Bagnall <douglas.bagnall@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
[abartlet@samba.org Adjusted to always use the PyObject_Call()
 as it is available in all of Samba's supported python versions]