Release notes

docs/releases.md

@@ -1472,6 +1472,7 @@ and the [ntfy Android app](https://github.com/binwiederhier/ntfy-android/release
 
 **Bug fixes + maintenance:**
 
+* Add mutex around message cache writes to avoid `database locked` errors ([#1397](https://github.com/binwiederhier/ntfy/pull/1397), thanks to [@timofej673](https://github.com/timofej673))
 * Add build tags `nopayments`, `nofirebase` and `nowebpush` to allow excluding external dependencies, useful for 
   packaging in Debian ([#1420](https://github.com/binwiederhier/ntfy/pull/1420), discussion in [#1258](https://github.com/binwiederhier/ntfy/issues/1258), thanks to [@thekhalifa](https://github.com/thekhalifa) for packaging ntfy for Debian/Ubuntu)