Blocked port 4369 ruins node addition badly

If connection attempt to remote epmd (port 4369) takes more than 7 seconds (for example if port is blocked by a firewall), any erlang distribution connection attempt will fail with reason timeout. Note that this will happen even when empd is not needed (it is not needed in most of the cases).
I think it should be ok to set a 2 second timeout for the erl_epmd:port_please(NodeName, IpAddr, Timeout) call in cb_dist in order to fix it. Basically in the worst case all connection attempts between nodes will take 2 seconds more than it normally would take, which should be ok.

7.6 is not affected because we removed any epmd support there.