CHANGELOG: Remove "(Unreleased)" from 2.3.0 changelog entry

Author: Holzhaus

CHANGELOG.md

@@ -1,6 +1,6 @@
 # Changelog
 
-## [2.3.0](https://launchpad.net/mixxx/+milestone/2.3.0) (Unreleased)
+## [2.3.0](https://launchpad.net/mixxx/+milestone/2.3.0)
 ### Hotcues ###
 * Add hotcue colors and custom labels by right clicking hotcue buttons or right clicking hotcues on overview waveforms [#2016](https://github.com/mixxxdj/mixxx/pull/2016) [#2520](https://github.com/mixxxdj/mixxx/pull/2520) [#2238](https://github.com/mixxxdj/mixxx/pull/2238) [#2560](https://github.com/mixxxdj/mixxx/pull/2560) [#2557](https://github.com/mixxxdj/mixxx/pull/2557) [#2362](https://github.com/mixxxdj/mixxx/pull/2362)
 * Mouse hover cues on overview waveform to show time remaining until the cue [#2238](https://github.com/mixxxdj/mixxx/pull/2238)