[MC-161902] Game crashes when a turtle ridden by an illager enters water

Summoned a Turtle with passenger to test recent bug fix ~~MC-158484~~, and no crash until the turtle was pushed into water or summoned in water.

To reproduce this summon turtle with passenger and lead them to water or summon them in water.

/summon turtle ~ ~ ~ {Passengers:[{id:vindicator}]}

19w39a: crash-2019-09-28_04.03.18-server.txt

Description: Ticking entity

java.lang.NullPointerException: Ticking entity
	at arf.r(SourceFile:329)
	at akn.c(SourceFile:1318)
	at akm.k(SourceFile:2302)
	at akn.k(SourceFile:490)
	at awk.k(SourceFile:39)
	at azc.k(SourceFile:114)
	at akm.h(SourceFile:2135)
	at akn.h(SourceFile:295)
	at awk.h(SourceFile:51)
	at akd.aO(SourceFile:1641)
	at akm.aO(SourceFile:2431)
	at wx.a(SourceFile:611)
	at wx.a(SourceFile:591)
	at bjk.a(SourceFile:648)
	at wx.a(SourceFile:388)
	at net.minecraft.server.MinecraftServer.b(SourceFile:843)
	at net.minecraft.server.MinecraftServer.a(SourceFile:782)
	at ecc.a(SourceFile:128)
	at net.minecraft.server.MinecraftServer.run(SourceFile:650)
	at java.lang.Thread.run(Unknown Source)