Remove code with no actual effect

Remove code with no actual effect

That code modifies \imprecise if it is not NULL, but
 - if a configuration is found, \imprecise will be set to in, clobbering
   the tentative changes done here;
 - if a configuration is not found, a last-resort loop will be run that
   will set the same member of \imprecise, also clobbering our changes.

Remove it since it does nothing that is looked at before being
forgotten. A way to get the intended outcome will be introduced later.