issue with _ in post type

Thank you for this simple solution. It has worked very well however there is an issue with the display of the calendar when the post type has an _ in the name. I was able to trace the issue to this after seeing it work on other post types. Then I created another one with an _ in the name and could replicate the issue. Our example post type is day_camp and I am using the following snippet in functions:

```
$types = array( 'run', 'program', 'day_camp', 'home_slide' );
foreach( $types as $type ) {
add_post_type_support( $type, 'unpublish' );
}
```

I've attached the screenshot displaying the behavior on that post type. I am not seeing any console errors, just the odd layout issue.

Start by reproducing the calendar display problem with the functions snippet and a post type containing an underscore, such as day_camp or home_slide, and compare it with run or program. Use the attached screenshot as the expected symptom; done means underscore-named post types display the calendar layout correctly without console errors.

Written by the indexing model from the issue text.