[MC-79208] kick form server if killed in a nether portal

on a smp server with half a heart me went in to a nether potal to the over world walked upstairs then lag sent me back in to the nether portal but oso took some fall dammage and died at that moment every body loged on at that time got kicked form theserver with the message (server closed) the server did not crash tho

Description: Ticking entity

java.lang.NullPointerException: Ticking entity
	at ayv.f(SourceFile:263)
	at are.b(SourceFile:123)
	at are.a(SourceFile:59)
	at sp.a(SourceFile:514)
	at wx.c(SourceFile:1749)
	at wx.K(SourceFile:303)
	at wx.t_(SourceFile:266)
	at xm.t_(SourceFile:69)
	at aqr.a(SourceFile:1407)
	at qu.a(SourceFile:600)
	at aqr.g(SourceFile:1385)
	at aqr.i(SourceFile:1278)
	at qu.i(SourceFile:478)
	at net.minecraft.server.MinecraftServer.A(SourceFile:608)
	at pp.A(SourceFile:299)
	at net.minecraft.server.MinecraftServer.z(SourceFile:532)
	at net.minecraft.server.MinecraftServer.run(SourceFile:448)
	at java.lang.Thread.run(Unknown Source)