Switch to Fragalysis API download for crystallographic data

[dotsdl]

From Frank von Delft:

Have you played with the new download functionality in Fragalysis, and did you get your head around how to use it? Because this Mpro.zip link is meant to be deprecated, or at the very least massively unreliable; whereas you are now meant to be able to precisely specify what it is you want to download, and generate an immortal link for yourself (technically: json command). It's vaguely self-documenting on the modal that pops up when you hit "Download Structures" button.