live restore: do not auto-dismiss stream job to improve error message and detection

upon failure. Otherwise, the job would disappear too quickly from the
job list and cannot be queried for the actual error anymore.

Relevant part of the error in an actual example:

Before:
> VM 112 qmp command 'blockdev-del' failed - Node 'drive-scsi0-pbs' is busy: node is used as backing hd of '#block046'

After:
> block job (stream) error: restore-drive-scsi0: No space left on device (io-status: ok)

Note that previously, it was not even detected that the stream job
failed and the error message is because the subsequent cleanup failed.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>

PVE/QemuServer.pm

@@ -7294,6 +7294,7 @@ sub pbs_live_restore {
 	    mon_cmd($vmid, 'block-stream',
 		'job-id' => $job_id,
 		device => "$ds",
+		'auto-dismiss' => JSON::false,
 	    );
 	    $jobs->{$job_id} = {};
 	}