FITS viewer on examine page points to a dead server

[willettk]

@eddedmondson recently had to shut down the server running at http://www.sdss.org.uk/ - this now throws a 404 error on the site looking for the frame.

None of the current files (either JPG or FITS versions) are hosted at the above website, so I don't believe we need it. Can the functionality be moved to one of the different Zooniverse servers?

The only files that reference the URL (as far as I know) are:

https://github.com/zooniverse/Galaxy-Zoo/blob/master/app/views/examine/examine.eco#L1
https://github.com/zooniverse/Galaxy-Zoo/blob/master/fits/app/controllers/fitsviewer.coffee#L6