Bump namespace to 04
diff --git a/build.rs b/build.rs
index cecf0e5..502a60b 100644
--- a/build.rs
+++ b/build.rs
@@ -4,7 +4,7 @@
         .cpp(true)
         .cpp_link_stdlib(None) // linked via link-cplusplus crate
         .flag_if_supported(cxxbridge_flags::STD)
-        .compile("cxxbridge03");
+        .compile("cxxbridge04");
     println!("cargo:rerun-if-changed=src/cxx.cc");
     println!("cargo:rerun-if-changed=include/cxx.h");
     println!("cargo:rustc-cfg=built_with_cargo");