org-table.el: Prevent an error from occurring

* lisp/org-table.el (org-table-justify-field-maybe): Fix bug.

Reported-by: Lester Longley <lester@ieee.org>
https://orgmode.org/list/CAA3095_oH2sH_a=nNeYEa=agZp7L2K8Vp2s-c7fN4M4Sro=stQ@mail.gmail.com

lisp/org-table.el

@@ -4407,7 +4407,7 @@ Optional argument NEW may specify text to replace the current field content."
 			  ((not new)
 			   (concat (org-table--align-field field width align)
 				   "|"))
-			  ((<= (org-string-width new) width)
+			  ((and width (<= (org-string-width new) width))
 			   (concat (org-table--align-field new width align)
 				   "|"))
 			  (t