zeroc-ice: share meta definition and clarify license

pkgs/development/libraries/zeroc-ice/3.6.nix

···
 { stdenv, lib, fetchFromGitHub
 , mcpp, bzip2, expat, openssl, db5
 , darwin, libiconv, Security
+, zeroc-ice # to share meta
 , cpp11 ? false
 }:
 
···
     rm -rf $out/share/slice
   '';
 
-  meta = with lib; {
-    homepage = "http://www.zeroc.com/ice.html";
-    description = "The internet communications engine";
-    license = licenses.gpl2;
-    platforms = platforms.unix;
-  };
+  inherit (zeroc-ice) meta;
 }

pkgs/development/libraries/zeroc-ice/default.nix

···
   meta = with lib; {
     homepage = "https://www.zeroc.com/ice.html";
     description = "The internet communications engine";
-    license = licenses.gpl2;
+    license = licenses.gpl2Only;
     platforms = platforms.unix;
     maintainers = with maintainers; [ abbradar ];
   };