python_ncbi_dbapi Connect: Explicitly NULL-terminate kwnames.

JIRA: CXX-13698.

git-svn-id: https://anonsvn.ncbi.nlm.nih.gov/repos/v1/trunk/c++@103033 78c7ea69-d796-4a43-9a09-de51944f1b03

Author: ucko

src/dbapi/lang_bind/python/python_ncbi_dbapi.cpp

@@ -3875,7 +3875,7 @@ Connect(PyObject *self, PyObject *args, PyObject *kwargs)
         try {
             static const char * const kwnames[] = {
                 "driver", "type", "dsn", "database", "user", "password",
-                "support_standard_interface", "extra"
+                "support_standard_interface", "extra", nullptr
             };
             PyObject *py_driver_name;
             PyObject *py_db_type;