Plane: fixed build with print() base change

ArduPlane/test.pde

@@ -373,7 +373,7 @@ test_modeswitch(uint8_t argc, const Menu::arg *argv)
 
     cliSerial->printf_P(PSTR("Control CH "));
 
-    cliSerial->println(FLIGHT_MODE_CHANNEL, DEC);
+    cliSerial->println(FLIGHT_MODE_CHANNEL, BASE_DEC);
 
     while(1) {
         delay(20);