Update README.md

fix url

24/LastHeard-Dashboard-Multislot/README.md

@@ -10,7 +10,7 @@ or my website [oe7drt.com](https://oe7drt.com) is well appreciated.
 
 [I made a blog post][blog post] about this screen.
 
-[blog post]: https://oe7drt.com/blog/nextion-dmr-last-heard-dashboard/
+[blog post]: https://oe7drt.com/posts/2020-02-16-nextion-dmr-last-heard-dashboard/
 
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