Treewide: update some problematic homepages

These URLs are reported as problematic by Repology.
It could be a permanent redirection
or the page does not exist anymore

pkgs/development/python-modules/dpkt/default.nix

@@ -11,7 +11,7 @@ buildPythonPackage rec {
 
   meta = with stdenv.lib; {
     description = "Fast, simple packet creation / parsing, with definitions for the basic TCP/IP protocols";
-    homepage = https://code.google.com/p/dpkt/;
+    homepage = "https://github.com/kbandla/dpkt";
     license = licenses.bsd3;
     maintainers = with maintainers; [ bjornfor ];
     platforms = platforms.all;