removed return nul in lawnchair dao

src/js/dao/lawnchair-dao.js

@@ -46,7 +46,7 @@ define(['lawnchair', 'lawnchairSQL', 'lawnchairIDB'], function(Lawnchair) {
             if (o) {
                 callback(o.object);
             } else {
-                callback(null);
+                callback();
             }
         });
     };

test/unit/lawnchair-dao-test.js

@@ -53,7 +53,7 @@ define(['js/dao/lawnchair-dao'], function(jsonDao) {
 
 								// should read empty
 								jsonDao.read(key, function(lastRead) {
-									equal(lastRead, null, 'Delete');
+									equal(lastRead, undefined, 'Delete');
 
 									start();
 								});