what shall I do?

[Alfred M. Szmidt]

   Just the link isn't ok. If this is non-commercial distribution it
   can only be done if the Andreas received an offer for accessing the
   source code. If that isn't the case, this is a GPL violation.

Well, not an offer directly, but just information on how to access it;
at least for non-commercial distribution (section 3 (c)).  I read it as
"giving the link" == "the information"; but forgot that it should be
accompanied with the actual distribution.

Anyway, the original poster didn't give enough information, so all we
can do is guess.

Cheerio.