Fixed a not enough arguments.

This PR fixed a below bug.

__REPRO STEPS__
1. Open edit entry screen.
2. Execute below javascript code. ( For example, using console of Google Chrome Developer Tools. )

```javascript
console.log(Template.process('test', { test: 'foo' }, { test: '[#|rp("foo","bar") test#]' }));
```
__EXPECTED__
It is output `"bar"`.

__RESULT__
It is output `"foo"`.