increase room server max uptime from 49 days to 136 years

examples/simple_room_server/MyMesh.h

@@ -88,6 +88,8 @@ struct PostInfo {
 
 class MyMesh : public mesh::Mesh, public CommonCLICallbacks {
   FILESYSTEM* _fs;
+  uint32_t last_millis;
+  uint64_t uptime_millis;
   unsigned long next_local_advert, next_flood_advert;
   bool _logging;
   NodePrefs _prefs;