Fix dvbs2

When not using auto-detect to find muxes, DVB-S2 gets skipped on load. This is due to the 5th field being incorrectly used as hierachy, when in fact, it is rolloff. Additionally, if it would have passed as such, the delivery system never gets set to DVB-S2.

Finally, in scan files, there is no such think as PSK_8, it's 8PSK.