[MC-121331] Client crashes when minimizing game while server disconnect window is displayed

The bug

The client crashes when the game is minimized while a server disconnect window is displayed. This happens when using the key combination ALT + TAB as well.

(17w45a) crash-2017-11-09_20.43.42-client.txt

Description: Unexpected error

java.lang.StackOverflowError: Unexpected error
	at bkz.e(SourceFile:649)
	at bkz.d(SourceFile:606)
	at bkz.d(SourceFile:617)
	at bkz.d(SourceFile:617)
	at bkz.d(SourceFile:617)
	at bkz.d(SourceFile:617)
	at bkz.d(SourceFile:617)
        ...

How to reproduce

Try to join an offline server
Minimize the game while the disconnect window is displayed