[client] restore accidentally deleted header
[client] restore accidentally deleted header

This was added by https://github.com/libra/libra/pull/4207 but accidentally removed by https://github.com/libra/libra/pull/4151

Closes: #4309
Approved by: sunmilee

aptos-labs/aptos-core,libra/libra,libra/libra,aptos-labs/aptos-core,aptos-labs/aptos-core,aptos-labs/aptos-core,libra/libra,libra/libra,aptos-labs/aptos-core,aptos-labs/aptos-core,aptos-labs/aptos-core,libra/libra