90's PCL -- a very minor bug

[smh@franz.com (Steve Haflich)]

In defclass.lisp there is a space after the ~ at the end of the line,
causing format to fail on the error message.

(defun expand-defclass (name supers slots options)
  ...
          (when (eq (car option) ':metaclass)
            (unless (legal-class-name-p (cadr option))
              (error "The value of the :metaclass option (~S) is not a~%~ 
                      legal class name."
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;HERE;;;;;;;;;;;;;;;;^
  ...