docs(changelog): specify changes for MqttOptions

rumqttc/CHANGELOG.md

@@ -8,6 +8,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## [Unreleased]
 
 ### Added
+- `MqttOptions::try_set_clean_session` to check if `clean_session` is `true` when `client_id` is an empty string.
 - Expose `EventLoop::clean` to allow triggering shutdown and subsequent storage of pending requests
 - Support for all variants of TLS key formats currently supported by Rustls: `PKCS#1`, `PKCS#8`, `RFC5915`. In practice we should now support all RSA keys and ECC keys in `DER` and `SEC1` encoding. Previously only `PKCS#1` and `PKCS#8` where supported.
 - TLS Error variants: `NoValidClientCertInChain`, `NoValidKeyInChain`.
@@ -16,6 +17,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Surfaced `AsyncClient`'s `from_senders` method to the `Client` as `from_sender`
 
 ### Changed
+- `MqttOptions::new` does not panic if the `client_id` is an empty string or starts with a whitespace.
 - Synchronous client methods take `&self` instead of `&mut self` (#646)
 - Removed the `Key` enum: users do not need to specify the TLS key variant in the `TlsConfiguration` anymore, this is inferred automatically.
 To update your code simply remove `Key::ECC()` or `Key::RSA()` from the initialization.