Reset pathsearchmode in Duke3D's GTK startup code
This was mainly observed as breaking MAP and SF2 file selection in NBlood and NotBlood's menus (starting from /
instead of the proper dir).
The problem is hidden in EDuke32 (and NetDuke32) due to a second call to CONFIG_ReadSetup
resetting pathsearchmode
. This call was originally introduced in 9df30428. Omitting it as a test leads to the same problem in EDuke32's menus if the GTK window is shown beforehand.