Don't swap signal handlers in md_shellescape(). md_shellescape() sets SIGINT and SIGQUIT to be ignored, storing the previous handlers, and restores them after the shell exits. But it mixed up the two handlers. Since the signals were usually handled by the same function, this fix doesn't have much effect, but anything that makes signal code less confusing is a good thing.

[Desktop Entry]
Encoding=UTF-8
Name=Rogue
GenericName=Rogue
Comment=The original curses-based adventure game
Exec=rogue
Icon=rogue.png
Terminal=true
Type=Application
Categories=Game;RolePlaying;
Version=1.0