Preliminary Checks

• I have already searched for existing issues and confirmed that this issue is not a duplicate

Is your feature request related to a problem? Please describe

In the Python sync version, updating exchange.rateLimit on an existing client works and requests adapt immediately.
In the asyncio version (ccxt.pro), changing rateLimit on an existing client does not seem to update the limiter.

Describe the solution you'd like

It would be nice to have a public function, that could change the rate_limit on an existing client.

Describe alternatives you've considered

I noticed that calling init_rest_rate_limiter() and setting tokenBucket = None makes it work, but I’m not sure if that’s the correct approach or what tokenBucket is used for.