Merge branch 'release/2.4.1' into production

lib/dao.js

@@ -1155,6 +1155,7 @@ DataAccessObject.prototype.updateAttributes = function updateAttributes(data, cb
             inst[key] = data[key];
             typedData[key] = inst[key];
             if (typeof typedData[key] === 'object' 
+              && typedData[key] !== null
               && typeof typedData[key].toObject === 'function') {
               typedData[key] = typedData[key].toObject();
             }

package.json

@@ -1,6 +1,6 @@
 {
   "name": "loopback-datasource-juggler",
-  "version": "2.4.0",
+  "version": "2.4.1",
   "description": "LoopBack DataSoure Juggler",
   "keywords": [
     "StrongLoop",