Remove unrelated comment

This is no longer unwrapping a legacy factory (which are gone).

src/core/ReactNativeComponent.js

@@ -57,7 +57,6 @@ function createInstanceForTag(tag, props, parentType) {
     );
     return new genericComponentClass(tag, props);
   }
-  // Unwrap legacy factories
   return new componentClass(props);
 }