Shorten length of array in config_ent to 4

The string array *messages[] in the config_ent structure, which is used
to store configuration data during runtime, has been shortened to have 4
strings, rather than 10, this is due to the fact that it's only used
with indeces IDLEMSG, SESSMSG, DAYMSG and NOLOGINMSG, or a variable with
one of these as a value. These indeces are all symbolic constants with
values 0 through 3, so only 4 members in the array are needed.

timeoutd.c

@@ -183,7 +183,7 @@ struct config_ent {
     int sessmax;
     int daymax;
     int warntime;
-    char *messages[10];
+    char *messages[4];
 };
 
 struct config_ent *config[MAXLINES + 1];