Currently, the seeder will timeout its connection with a node after 30
seconds on non-Tor connections. However, this can cause the connection
to timeout rather frequently because the node software also delays
sending addr messages by 30 seconds (see `AVG_ADDRESS_BROADCAST_INTERVAL`
in `net_processing.cpp`. Adding some buffer time for various situations
will prevent false negatives and unintended connection timeouts.
Currently, it is too costly to pull `AVG_ADDRESS_BROADCAST_INTERVAL`
into the seeder, so a commment has also been added so the code shows up
if `AVG_ADDRESS_BROADCAST_INTERVAL` is grep'd for.