I have no idea how to reassign Space to jump, but it seems that its not possible.
Somehow Ive messed up my config yesterday, so space was no longer jump. I tried to reassign space as jump hotkey but it did not work. Neither with shift or tab keys, so I guess it does not support special characters.
That leads to the problem, that you cant assign certain keys to actions once youve messed it up.
Steps to Reproduce:
Simple:
Assign any non-special key to jump and try to reassign space, shift, tab - it wont work.