[BUG][PLAYER] crash after close

[mobius]

if you close NL by Alt-f4 during a level the program closes but you get an error message:

"exception EAcessViolation in module NeoLemmix.exe at 000F8023
Read of address 00688168"

I just downloaded the latest version (...18) but I noticed this for several versions now (kept forgetting about it).

[namida]

This isn't critical, so I won't release a hotfix. However, I'll fix it in the new-formats version, and if any future hotfixes for the current version do come out, I'll include the fix for this if possible.

[Nepster]

This is fixed in the current new-formats version.