commit: Correct the perhaps_init_unseen_key_defaults GTK code; don't override X11 fonts.

[Stephen J. Turnbull]

Aidan Kehoe writes:

 > Basically, the GTK build is unstable and undertested.

And based on an *obsolete* and *unsupported* version of GTK.

 > Bugfixes and further investigation welcome.

IMHO, please, no.  Upgrade to GTK v2 first, please!  please, please, ...