Update changelog

Author: tulir

CHANGELOG.md

@@ -9,9 +9,12 @@
     for relative paths, and `sqlite:/path.db` instead of `sqlite:////path.db`
     for absolute paths.
   * Bridge configs do this migration automatically.
+* *(util.async_db)* Added warning log if using SQLite database path that isn't
+  writable.
 * *(client)* Stabilized support for asynchronous uploads.
   * `unstable_create_msc` was renamed to `create_mxc`, and the `max_stall_ms`
     parameters for downloading were renamed to `timeout_ms`..
+* *(crypto)* Added option to not rotate keys when devices change.
 
 ## v0.19.16 (2023-05-26)