valgrind.meta.homepage: update

Old one redirects here.  Good to use HTTPS.

Author: alyssais

pkgs/development/tools/analysis/valgrind/default.nix

@@ -115,7 +115,7 @@ stdenv.mkDerivation rec {
   };
 
   meta = {
-    homepage = "http://www.valgrind.org/";
+    homepage = "https://valgrind.org/";
     description = "Debugging and profiling tool suite";
 
     longDescription = ''