BUG/MEDIUM: spoa/python: Fixing PyObject_Call positional arguments

As per https://docs.python.org/3/c-api/object.html#c.PyObject_Call,
positional arguments should be an empty tuple when not used.
Previously the code had a dictionary instead of tuple. This commit is to
fix it and use tuple to avoid unexpected consequences

This patch must be backported as far as 2.0.
1 file changed