add board.setAdcMultiplier to room server and sensor

examples/simple_room_server/MyMesh.cpp

@@ -641,6 +641,8 @@ void MyMesh::begin(FILESYSTEM *fs) {
   updateAdvertTimer();
   updateFloodAdvertTimer();
 
+  board.setAdcMultiplier(_prefs.adc_multiplier);
+
 #if ENV_INCLUDE_GPS == 1
   applyGpsPrefs();
 #endif