update changelog

Author: antonilol

changelog.md

@@ -3,6 +3,8 @@ when upgrading from a version of rust-sdl2 to another.
 
 ### Next
 
+[PR #1435](https://github.com/Rust-SDL2/rust-sdl2/pull/1435) **BREAKING CHANGE** Fix some undefined behavior. Breaking changes: `mixer::Chunk`'s fields are now private and callbacks to `TimerSubsystem::add_timer` must now live for `'static`, also allowing some lifetime parameters to be removed.
+
 [PR #1461](https://github.com/Rust-SDL2/rust-sdl2/pull/1461) **BREAKING CHANGE** Added new SensorType variants: LeftGyroscope, RightGyroscope, LeftAccelerometer, RightAccelerometer
 
 [PR #1461](https://github.com/Rust-SDL2/rust-sdl2/pull/1461) **BREAKING CHANGE** Sensor::get_data now returns correct SensorData::Gyro enum