Deterministic crash when bridging in the end from the center iland to external ones, while the dragon is alive.

This is a deterministic crash, happens all the times.

I did not test to kill the Dragon and try bridging again.

To reproduce: enter the end, dodge the dragon and start bridging, likely to the North.

 ```Version: 1.14.60.5
OS: Linux
Server start: 2020-05-28 17:29:28 UTC
Dmp timestamp: 2020-05-29 00:25:45 UTC
Upload Date: 2020-05-29 00:25:45 UTC
Session ID: c9f8bd11-984a-4f72-8a1f-85d726ba5b7f
Commit hash:
Build id: development
CrashReporter Key: 5b5cb041-9b77-3cf8-9245-0594d00f81aa```

```
gamemode=survival
difficulty=hard
allow-cheats=false
max-players=30
online-mode=true
white-list=false
server-port=19132
server-portv6=19133
view-distance=12
tick-distance=12
player-idle-timeout=0
max-threads=6
level-seed=265697407
default-player-permission-level=visitor
texturepack-required=true
content-log-file-enabled=true
compression-threshold=512
server-authoritative-movement=false
player-movement-score-threshold=20
player-movement-distance-threshold=0.3
player-movement-duration-threshold-in-ms=500
correct-player-movement=false
```