[staging-next] protobufc: fix build (#497358)

pkgs/by-name/pr/protobufc/package.nix

@@ -4,7 +4,7 @@
   fetchFromGitHub,
   autoreconfHook,
   pkg-config,
-  protobuf,
+  protobuf_33,
   zlib,
   buildPackages,
 }:
@@ -32,11 +32,11 @@ stdenv.mkDerivation (finalAttrs: {
   ];
 
   buildInputs = [
-    protobuf
+    protobuf_33
     zlib
   ];
 
-  env.PROTOC = lib.getExe buildPackages.protobuf;
+  env.PROTOC = lib.getExe buildPackages.protobuf_33;
 
   meta = {
     homepage = "https://github.com/protobuf-c/protobuf-c/";