Static deltachat::net::dns::LOOKUP_HOST_CACHE

static LOOKUP_HOST_CACHE: Lazy<RwLock<HashMap<String, Vec<IpAddr>>>>

Map from hostname to IP addresses.

NOTE: sync RwLock is used, so it must not be held across .await to avoid deadlocks. See https://docs.rs/tokio/1.40.0/tokio/sync/struct.Mutex.html#which-kind-of-mutex-should-you-use and https://stackoverflow.com/questions/63712823/why-do-i-get-a-deadlock-when-using-tokio-with-a-stdsyncmutex.