message: Check the user onboarding the new validator is actually in the validator set
diff: @@ -35,7 +35,7 @@ module DiemAccount {
  use 0x1::DiemId;
  //////// 0L ////////
  use 0x1::VDF;
  - // use 0x1::Globals;
  + use 0x1::DiemSystem;
  use 0x1::TowerState;
  use 0x1::Testnet::is_testnet;
  use 0x1::FIFO;
  @@ -516,6 +516,8 @@ module DiemAccount {
  ):address acquires DiemAccount, Balance, AccountOperationsCapability, CumulativeDeposits, SlowWalletList { //////// 0L ////////
  let sender_addr = Signer::address_of(sender);
  // Rate limit spam accounts.
  + // check the validator is in set before creating
  + assert(DiemSystem::is_validator(sender_addr), Errors::limit_exceeded(120101));
  assert(TowerState::can_create_val_account(sender_addr), Errors::limit_exceeded(120102));
  // Check there's enough balance for bootstrapping both operator and validator account
  assert(
  