fix a compile warning

src/debug.lisp

@@ -17,6 +17,7 @@
   "Initialize the debug module.
 Check if the current thread is named `repl-thread' and if not,
 start the swank server to accept remote connection."
+  (declare (ignore argv))
   (format t "Initialize Debug module~%")
   (when (not (string= (thread:thread-name (thread:current-thread)) "repl-thread"))
     #+swank