Log Message:
sqlite: updated to 3.23.1

SQLite Release 3.23.1:
Fix two problems in the new LEFT JOIN strength reduction optimization.
Fix misbehavior of the FTS5 xBestIndex method.
Fix a harmless reference to an uninitialized virtual machine register.
Fix the CLI so that it builds with -DSQLITE_UNTESTABLE
Fix the eval.c extension so that it works with PRAGMA empty_result_callbacks=ON.
Fix the generate_series virtual table so that it correctly returns no rows if \ 
any of its constraints are NULL.
Performance enhancements in the parser.