[comp.emacs.xemacs] Fix to customization for 'Manual-switches' in 'man.el'

[Stephen J. Turnbull]

John Paul Wallington writes:

 > I guess the variable's default value, nil, matches both the const nil  
 > form and the repeat string form.  If the customize interface shows the  
 > first applicable choice then it would be necessary to put the const  
 > nil choice first lest it be redundant.

D'oh.  It *is* redundant, isn't it.  Unless somebody comes up with a
good reason not to, I'm just going to get rid of the const nil and
parent choice widget, too.