Deleting just released nettle-3 package

[Dr. Volker Zell]

Hi

I just realized that gnutls cannot be build with the latest just
uploaded nettle-3.0 packages for both architectures.

Should I upload a version bumped nettle-2.7-2 package ? Then the nettle
3.0 specific files

  libnettle5-3.0-1.tar.xz
  libhogweed3-3.0-1.tar.xz
  libnettle-devel-3.0-1.tar.xz
  nettle-3.0-1.tar.xz
  nettle-3.0-1-src.tar.xz

should be removed.  

Ciao
  Volker