DVB-S: determine satellite number was off

Use szap-s2 method instead, this seems to give consistent results now

dvb.c

@@ -425,7 +425,7 @@ static int FrontendDoDiseqc(void)
         struct dvb_diseqc_master_cmd cmd =
             { {0xe0, 0x10, 0x38, 0xf0, 0x00, 0x00}, 4};
         cmd.msg[3] = 0xf0 /* reset bits */
-                          | ((i_satnum - 1) << 2)
+                          | ((i_satnum * 4) & 0x0f)
                           | (fe_voltage == SEC_VOLTAGE_13 ? 0 : 2)
                           | (fe_tone == SEC_TONE_ON ? 1 : 0);