Upstream has released updates that appear to apply and compile correctly.
This update has not been tested by PaperMC and as with ANY update, please do your own testing
Bukkit Changes:
4b08dbc5 PR-752: Make Leaves Waterlogged
de323fc9 Downgrade dependency version
CraftBukkit Changes:
c3f219edb Fix missing abstract in CraftLeaves
886e6d8c8 SPIGOT-7038: Setting title or subtitle to empty string causes the player to disconnect
6c302a5e3 Make Leaves Waterlogged
53b681be5 Downgrade dependency version
Spigot Changes:
ee737122 Fixed system messages shown in action bar
f343df82 SPIGOT-7036: Don't use CHAT message type
63a06049 SPIGOT-7035: Actionbar Sending in Main Chat
Jake Potrebic
Nassim Jahnke