api server /backup/kill command is required parameter, not optional

[UnamedRus]

https://github.com/Altinity/clickhouse-backup#api

Documentation

Optional query argument command may contain the command name to kill, or if it is omitted then kill the last "in progress" command.

In code

clickhouse-backup/pkg/server/server.go

Line 434 in 9162a08

return actionsResults, errors.New("kill <command> parameter empty")

Plus, it seems, it doesn't check that parameter actually named command, just use first parameter value?