Message 304172 - Python tracker

The following code causes a crash:
import sqlite3
cursor = sqlite3.Cursor.__new__(sqlite3.Cursor)
cursor.close()

this is because pysqlite_cursor_close() (in Modules/_sqlite/cursor.c) assumes
that `self->connection` is not NULL, and passes it to pysqlite_check_thread(),
which crashes.


I would open a PR to fix this soon.