Account for WIN_MESSAGE == WIN_ERR in free_window_info

[fmayer]

In fact, it is always WIN_ERR in the caller in line 1403

This tripped UBSan's bounds checks

[heiner]

Note that we inherited this drastic issue from upstream NetHack https://github.com/NetHack/NetHack/blob/NetHack-3.6/win/tty/wintty.c#L1558

[heiner]

But 3.7 fixed the same issue: NetHack/NetHack@f9d7bc6

[fmayer]

Hmm, CI crashed with this:

    gmake[2]: *** [dat/earth.lev] Segmentation fault (core dumped)
    gmake[2]: *** Deleting file `dat/earth.lev'
    gmake[2]: *** Waiting for unfinished jobs....
    gmake[1]: *** [dat/CMakeFiles/dat.dir/all] Error 2
    gmake[1]: *** Waiting for unfinished jobs....

[heiner]

@StephenOman do you have any context on this?

[StephenOman]

Not yet. Doesn't look related to this PR. Error is:

gmake[2]: *** [dat/earth.lev] Segmentation fault (core dumped)

[fmayer]

Can we rerun CI here? Seems like the issues was solved in #48 .

[heiner]

Kicked off a CI rerun. We can merge regardless though, this change is good.