message: fix early deletion of wasm state schema
diff: @@ -950,9 +950,13 @@ WasmResult Context::setProperty(absl::string_view path, absl::string_view value)
  WasmResult Context::declareProperty(absl::string_view path,
  std::unique_ptr<const WasmStatePrototype> state_prototype) {
  + // Do not delete existing schema since it can be referenced by state objects.
  + if (state_prototypes_.find(path) == state_prototypes_.end()) {
  state_prototypes_[path] = std::move(state_prototype);
  return WasmResult::Ok;
  }
  + return WasmResult::BadArgument;
  +}
  WasmResult Context::log(uint32_t level, absl::string_view message) {
  switch (static_cast<spdlog::level::level_enum>(level)) {
  