Update release date.

Author: mondalaci

Diff for: CHANGELOG.md

@@ -6,7 +6,7 @@ The format is loosely based on [Keep a Changelog](http://keepachangelog.com/en/1
 
 Every Agent version includes the most recent firmware version. See the [firmware changelog](https://github.com/UltimateHackingKeyboard/firmware/blob/master/CHANGELOG.md).
 
-## [1.2.13] - 2019-07-14
+## [1.2.13] - 2019-09-13
 
 Firmware: 8.5.**4** [[release](https://github.com/UltimateHackingKeyboard/firmware/releases/tag/v8.5.4)] | Device Protocol: 4.4.0 | User Config: 4.0.1 | Hardware Config: 1.0.0