message: Fix upgrade test config and chainspec.
  Joining nodes can only catch up if the block time is much longer than
  the sync state interval.
diff: @@ -78,7 +78,7 @@ standstill_timeout = '0sec'
  # Request the latest protocol state from a random peer periodically, with this interval.
  # '0sec' means it is disabled and we never request the protocol state from a peer.
  -sync_state_interval = '1sec'
  +sync_state_interval = '50ms'
  # Log inactive or faulty validators periodically, with this interval.
  # '0sec' means it is disabled and we never print the log message.
  