fix in the example, thanks to Pino ZP4KFX

git-svn-id: https://hamlib.svn.sourceforge.net/svnroot/hamlib/trunk@2946 7ae35d74-ebe9-4afe-98af-79ac388436b8

tests/rigctld.8

@@ -510,7 +510,7 @@ returned to the client.
 .PP
 An example response to a \fI+\\set_mode\fP command (note the prepended '+'):
 .sp
-$ echo "+F USB 2400" | nc -w 1 localhost 4532
+$ echo "+M USB 2400" | nc -w 1 localhost 4532
 .br
 set_mode: USB 2400
 .br