added build flag to enable/disable boot advert

examples/simple_room_server/main.cpp

@@ -77,7 +77,9 @@ void setup() {
 #endif
 
   // send out initial zero hop Advertisement to the mesh
+#if ENABLE_ADVERT_ON_BOOT == 1
   the_mesh.sendSelfAdvertisement(16000, false);
+#endif
 }
 
 void loop() {