Update changelog

Author: michaelnisi

CHANGELOG.md

@@ -11,7 +11,7 @@
 - `apollo-codegen-scala`
   - <First `apollo-codegen-scala` related entry goes here>
 - `apollo-codegen-swift`
-  - <First `apollo-codegen-swift` related entry goes here>
+  - Prevent compiler warnings for redundant access-level modifiers when using `--namespace` [1241](https://github.com/apollographql/apollo-tooling/pull/1241)
 - `apollo-codegen-typescript`
   - <First `apollo-codegen-typescript` related entry goes here>
 - `apollo-env`