refactor: Avoid locking cs_main in ProcessNewBlockHeaders
refactor: Avoid locking cs_main in ProcessNewBlockHeaders

Former-commit-id: 579d4e045bcbea36f014a199ea04fedfb70e01e6
syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin