Upstream has released updates that appears to apply and compile correctly.
This update has not been tested by PaperMC and as with ANY update, please do your own testing
CraftBukkit Changes:
632449b6 SPIGOT-4349: End portal has wrong TeleportCause
3eb8af23 SPIGOT-4348: Use online player for setting skull owner if possible
62b2a5e05e