plugins/python/sudo_python_module.c: fix options_as_dict if no equal sign

The intented behaviour was that those get skipped, but the PyList_GetItem
sets the interpreter into error state, so python has raised exception.

plugins/python/sudo_python_module.c

@@ -171,6 +171,7 @@ python_sudo_options_as_dict(PyObject *py_self, PyObject *py_args)
         if (py_value == NULL) {  // skip values without a key
             Py_CLEAR(py_config);
             Py_CLEAR(py_splitted);
+            PyErr_Clear();
             continue;
         }