Relatively straightforward. Our decision to make block job
speed a long keeps haunting us on new API.
* src/remote/remote_protocol.x (remote_domain_block_commit_args):
New struct.
* src/remote/remote_driver.c (remote_driver): Enable it.
* src/remote_protocol-structs: Regenerate.
* src/rpc/gendispatch.pl (long_legacy): Exempt another bandwidth.