c-ares: use https for homepage

pkgs/development/libraries/c-ares/default.nix

···
 
   meta = with stdenv.lib; {
     description = "A C library for asynchronous DNS requests";
-    homepage = http://c-ares.haxx.se;
+    homepage = https://c-ares.haxx.se;
     license = licenses.mit;
     platforms = platforms.all;
   };