Fixed: Samples table wont load if missing info

Replaced 'in info' and info.hasOwnProperty.
I don't know why info.hasOwnProperty() or 'library_prep' in info wont evaluate to false when info is an object that has no 'library_prep'. Maybe something to do with Jquery $.each or $.getJSON?

@ewels or anyone else know why? In any case, it is now fixed.