Remove duplicate &optional

In emacs-26 duplicate &optional is an error.

  ...
  lyskom.el:42124:26:Error: Duplicate &optional
  make: *** [Makefile:195: lyskom.elc] Error 1

src/ChangeLog

+2018-04-10  Christer Ekholm  <che@chrekh.se>
+
+	* commands2.el (lyskom-list-news): Remove Duplicate &optional
+
 2016-07-07  Christer Ekholm  <che@chrekh.se>
 
 	* parse.el: Remove unused function lyskom-parse-coded-string

src/commands2.el

@@ -948,7 +948,7 @@ See `kom-allow-incompleteness'."
                             lyskom-iter-list-news-total-confs))))
 
 
-(defun lyskom-list-news (&optional callback &optional callback-args)
+(defun lyskom-list-news (&optional callback callback-args)
   "With no arguments, returns a list of tuples (unread . conf-stat).
 When called with a CALLBACK function, this function is called
 iteratively as the list is built up. This function should take the two