Update CHANGELOG.md (#4537)

CHANGELOG.md

@@ -1,6 +1,6 @@
-#Change Log
+# Change Log
 All notable changes to this project will be documented in this file.
-`AFNetworking` adheres to [Semantic Versioning](http://semver.org/).
+`AFNetworking` adheres to [Semantic Versioning](https://semver.org/).
 
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