changelog: add entry about O!MPD fix

Author: MichaIng

CHANGELOG.txt

@@ -4,6 +4,7 @@ v9.12
 Enhancemnts:
 - DietPi-Software | WiringPi: Added support for Orange Pi boards, using the wiringOP sources from Xunlong: https://github.com/orangepi-xunlong/wiringOP
 - DietPi-Software | Spotifyd: Added support for ARMv8 and x86_64 Bookworm/Trixie systems, supported with the latest Spotifyd release.
+- DietPi-Software | O!MPD: Resolved an issue where changing the config.php from within the web UI and storing covers did not work due to missing permissions. Many thanks to @praveensg for reporting this issue: https://dietpi.com/forum/t/22993
 
 Bug fixes: