Comment 3 for bug 1938021

Okay this looks like a simple RPC call timeout to the conductor as the test is setting this timeout to 1 [1] while the actual call and task within the conductor can easily take longer than this [2][3]. I'm not sure why we are suddenly seeing this but I think the easiest thing to do here is to move the call over to long_rpc_timeout?

[1] https://github.com/openstack/nova/blob/72c8722e09a47794fc5412a14587a74e79195fca/nova/tests/functional/test_cross_cell_migrate.py#L73-L75
[2] https://github.com/openstack/nova/blob/72c8722e09a47794fc5412a14587a74e79195fca/nova/conductor/rpcapi.py#L459-L468
[3] https://github.com/openstack/nova/blob/72c8722e09a47794fc5412a14587a74e79195fca/nova/conductor/tasks/cross_cell_migrate.py#L1027-L1050