update changelog

CHANGELOG.md

@@ -1,7 +1,7 @@
 NRPE Changelog
 ==============
 
-[4.0.3](https://github.com/NagiosEnterprises/nrpe/releases/tag/nrpe-4.0.3) - 2020-??-??
+[4.0.3](https://github.com/NagiosEnterprises/nrpe/releases/tag/nrpe-4.0.3) - 2020-04-28
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 **FIXES**
 - Fixed nasty_metachars not being read from config file (#235) (Sebastian Wolf)