Merge pull request #952 from abhayastudios/master

Fix on fix for issue #947

Author: EddyVerbruggen

src/firebase.ios.ts

@@ -1833,7 +1833,7 @@ function fixSpecialField(item): any {
     });
   } else if (isDocumentReference(item)) {
     return item.ios;
-  } else if (typeof item === "object") {
+  } else if (typeof item === "object" && item.constructor === Object) {
     return fixSpecialFields(item);
   } else {
     return item;