Fix compiler warning

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@4302 65c4cc65-6c06-0410-ace0-fbb531ad65f3

cli.c

@@ -27,6 +27,7 @@
 #include <stdio.h>
 #include <signal.h>
 #include <string.h>
+#include <ctype.h>
 /* For rl_filename_completion */
 #include "editline/readline/readline.h"
 /* For module directory */