Fix buttons target error

When including the Buttons plugin on any page, I got some weird error whenever a click event was triggered on an `<a>` element with a hash `href` attribute, like:

```html
<a href="#some-id">Click me</a>
```

I would get a:

```
Fix for Uncaught TypeError: Cannot read property 'target' of undefined on line 58
```

Double checking for the `originalEvent`'s target did the trick for me.