docs: fix broken README reference in README.md

README.md

@@ -1,4 +1,4 @@
-# [![PrivateBin](https://cdn.rawgit.com/PrivateBin/assets/master/images/preview/logoSmall.png)](https://privatebin.info/)
+# [![PrivateBin](https://raw.githubusercontent.com/PrivateBin/assets/master/images/preview/logoSmall.png)](https://privatebin.info/)
 
 *Current version: 2.0.3*