Update on instance of gimp2 checksum failure

[David Evans]

As a follow up, it turns out the site in question[1] is broken and
redirects to
the sites home page when trying to access the url of the distribution. 
So the
checksums returned were for this home page. 

GIMP developers have removed the site from their SVN although this will not
be reflected on their home page for a while.

So nothing sinister at work here.

Dave

[1] http://trac.macports.org/ticket/17057