[DownloadScheduler] Make new speed values take effect in pyLoad
[DownloadScheduler] Make new speed values take effect in pyLoad

Currently, DownloadScheduler sets the new `limit_speed` and `max_speed` values.
However, a submit from the "Download" config GUI page is required for them to
take effect. This change makes DownloadScheduler to automatically submit the new
values so they take effect immediately.

vuolter/pyload,vuolter/pyload,vuolter/pyload