Turns security back on in the members directory

This is so non-logged in people can't alter the database.  Mark Leigh
pointed this out to me when sending me the code, and said "Can't remember
why it ended up like this, the auth code is there but commented out."

members/submit.php

@@ -15,8 +15,8 @@ global $cfg_membershipID;
 
 if(!$sec->isLoggedIn())
 {
-//        header ("location: ../login.php");
-//        exit();
+        header ("location: ../login.php");
+        exit();
 }
 
 ?>