Update rigctld.1 man page

https://github.com/Hamlib/Hamlib/issues/404

doc/man1/rigctld.1

@@ -339,10 +339,17 @@ below).
 Enables timeout when VFO twiddling is detected.  Some functions will be ignored.
 .IP
 Should only be needed when controlling software should be "paused"
-.B -v
 so you can move the VFO.  Continuous movement extends the timeout.
 .
 .TP
+.BR \-x ", " \-\-uplink=option
+1=Sub, 2=Main 
+.IP
+For GPredict use to ignore get_freq for Sub or Main uplink VFO.
+.IP
+Should allow downlink VFO movement without confusing GPredict or the uplink
+.
+.TP
 .BR \-Z ", " \-\-debug\-time\-stamps
 Enable time stamps for the debug messages.
 .IP