ko.meteor.findOne should not construct view_model when result undefined

[steveluscher]

Desired outcome:

p = ko.meteor.findOne(People, {name: 'Does Not Exist'}, {view_model: Person});
p(); // undefined

Actual outcome:

p = ko.meteor.findOne(People, {name: 'Does Not Exist}, {view_model: Person}); // RangeError: Maximum call stack size exceeded.