Fix #286: Lack of continuous tuning and monitor lockout while holding up/down button in monitor mode.

app/main.c

@@ -639,6 +639,8 @@ static void MAIN_Key_UP_DOWN(bool bKeyPressed, bool bKeyHeld, int8_t Direction)
 					return;
 				}
 				gTxVfo->freq_config_RX.Frequency = frequency;
+				BK4819_SetFrequency(frequency);
+				BK4819_RX_TurnOn();
 				gRequestSaveChannel = 1;
 				return;
 			}