AP_RCProtocol: remove pointless 100kbaud speed change

added.opened is set to false.  Next time we check_added_uart, the baud
rate is unconditionally set in each of the phases.  Thus this line has
no effect except to confuse the reader

libraries/AP_RCProtocol/AP_RCProtocol.cpp

@@ -303,7 +303,6 @@ void AP_RCProtocol::check_added_uart(void)
             if (added.phase > CONFIG_420000_8N1) {
                 added.phase = (enum config_phase)0;
             }
-            added.baudrate = (added.baudrate==100000)?115200:100000;
             added.opened = false;
         }
     }