chore(infea): add missing callback invocation for lambda@edge function

This function conditionally rewrites non-gz URLs to gz. The zip files are conditionally excluded. However, in case o zip file the "done" callback was not called at the end of the function, so the response was incorrect.

Here I add the callback invocation at the end of the function, so that requests for zip files are correctly replied to.

infra/rewriteToGzip.lambda.js

@@ -11,4 +11,6 @@ exports.handler = (event, context, callback) => {
     request.uri += '.gz'
     callback(null, request)
   }
+
+  callback(null, request)
 }