Constant deltachat::constants::SECUREJOIN_WAIT_TIMEOUT

pub(crate) const SECUREJOIN_WAIT_TIMEOUT: u64 = 15;

How long a 1:1 chat can’t be used for sending while the SecureJoin is in progress. This should be 10-20 seconds so that we are reasonably sure that the app remains active and receiving also on mobile devices. See also crate::chat::CantSendReason::SecurejoinWait.