[MC-137266] Colon in 'Direct Connect' menu crashes game

The bug

When you enter just a colon ( : ) and press Enter in 'Direct Connect', your game will crash.

How to reproduce

Open the "Direct Connect" menu
Enter ":" in the field
Press Enter to connect
→ Your game crashes

Crash report

1.13.1: crash-2018-10-14_12.35.37-client.txt

Description: keyPressed event handler

java.lang.ArrayIndexOutOfBoundsException: 0
	at crh.a(SourceFile:61)
	at cjj.<init>(SourceFile:35)
	at clw.a(SourceFile:332)
	at clw.confirmResult(SourceFile:210)
	at cjo.h(SourceFile:65)
	at cjo.keyPressed(SourceFile:91)
	at cfp.a(SourceFile:389)
	at cfp$$Lambda$1029/1333511278.run(Unknown Source)
	at ckc.a(SourceFile:430)
	at cfp.a(SourceFile:387)
	at cfp$$Lambda$841/1050196275.invoke(Unknown Source)
	at org.lwjgl.glfw.GLFWKeyCallbackI.callback(GLFWKeyCallbackI.java:37)
	at org.lwjgl.system.JNI.invokeV(Native Method)
	at org.lwjgl.glfw.GLFW.glfwWaitEventsTimeout(GLFW.java:3108)
	at cgc.a(SourceFile:321)
	at cfs.c(SourceFile:875)
	at cfs.a(SourceFile:395)
	at net.minecraft.client.main.Main.main(SourceFile:144)