Fix nscondefine issue for MAINTENANCE_MODE, a=chris

diff --git a/src/configs/Config.php b/src/configs/Config.php
index f11a35097..53ccfbb06 100755
--- a/src/configs/Config.php
+++ b/src/configs/Config.php
@@ -333,7 +333,7 @@ nsdefine('QUERY_INFO', 2);
 /** bit of DEBUG_LEVEL used to indicate php messages should be displayed*/
 nsdefine('ERROR_INFO', 4);
 /** Maintenance mode restricts access to local machine*/
-nsdefine("MAINTENANCE_MODE", false);
+nsconddefine("MAINTENANCE_MODE", false);
 /** Constant used to indicate lasting an arbitrary number of seconds */
 nsdefine('FOREVER', -2);
 /** Number of seconds in a day*/