Update to Minecraft 1.16.3

By: md_5 <git@md-5.net>

paper-server/nms-patches/WorldServer.patch

@@ -319,7 +319,7 @@
 +
 +        worldDataServer.a(worldserver1.getWorldBorder().t());
 +        worldDataServer.setCustomBossEvents(this.server.getBossBattleCustomData().save());
-+        convertable.a(this.server.f, this.worldDataServer, this.server.getPlayerList().save());
++        convertable.a(this.server.customRegistry, this.worldDataServer, this.server.getPlayerList().save());
 +        // CraftBukkit end
      }