[BW]: [Fix] Fixed random crash while closing the application: main thread executing bts::application::close should wait until connection_loop will be completed to avoid crash while referencing bts::detail::application_impl members.
[BW]: [NIP] Preliminary changes for solving application hang while closing server connections. Not fixed yet.
[BW]: [NIP] bts::level_pod_map::open throws dedicated fc::db_in_use_exception