config-wizard: use the level 0 keysym whenever it’s unambiguous

config-wizard: use the level 0 keysym whenever it’s unambiguous

From the code:

    Try to use the keysym on the first level (lower-case). In case
    this doesn’t make it ambiguous (think of a keyboard layout
    having '1' on two different keys, but '!' only on keycode 10),
    we’ll stick with the keysym of the first level.

    This reduces a lot of confusion for users who switch keyboard
    layouts from qwerty to qwertz or other slight variations of
    qwerty (yes, that happens quite often).