MFH: r548068
net/enet: update to 1.3.16
From ChangeLog: https://github.com/lsalzman/enet/blob/master/ChangeLog
- fix bug in unreliable fragment queuing
- use single output queue for reliable and unreliable packets for saner ordering
- revert experimental throttle changes that were less stable than prior algorithm
Reported by: portscout
Approved by: ports-secteam (blanket, runtime fix)