nanomsg: buildInputs -> nativeBuildInputs

Using `nativeBuildInputs` instead of `buildInputs` for the cmake dependency since using `buildInputs` prevents the package from being cross compiled to arm.

pkgs/development/libraries/nanomsg/default.nix

@@ -11,7 +11,7 @@ stdenv.mkDerivation rec {
     sha256 = "01ddfzjlkf2dgijrmm3j3j8irccsnbgfvjcnwslsfaxnrmrq5s64";
   };
 
-  buildInputs = [ cmake ];
+  nativeBuildInputs = [ cmake ];
 
   meta = with stdenv.lib; {
     description= "Socket library that provides several common communication patterns";