message: more precise exception
diff: @@ -92,7 +92,7 @@ void apply_eosio_newaccount(apply_context& context) {
  }
  auto existing_account = db.find<account_object, by_name>(create.name);
  - EOS_ASSERT(existing_account == nullptr, action_validate_exception,
  + EOS_ASSERT(existing_account == nullptr, account_name_exists_exception,
  "Cannot create account named ${name}, as that name is already taken",
  ("name", create.name));
  