Update iot-modelsrepository changelog (Azure#15441)

New release date

Author: Yoseph Maguire

sdk/iot/iot-modelsrepository/CHANGELOG.md

@@ -1,6 +1,6 @@
 # Release History
 
-## 1.0.0-beta.1 (2021-05-26)
+## 1.0.0-beta.1 (2021-05-27)
 
 With [#14863](https://github.com/Azure/azure-sdk-for-js/pull/14863), this is the first release of the @azure/iot-modelsrepository package.