Select input value issue

Thanks for the great library.

I came across an issue where I had the following options in my select

```
'' => ' -- Any --',
'0' => 'Studio',
'1' => '1 Bedroom',
'2' => '2 Bedrooms',
```

Unfortunately because php treats `'' == 0` as `true`, both of the top two options are treated as selected.

I've updated the comparison to `$val === $value` to fix this issue.