CC-5109: Fix race-condition when updating cc_pref table

-not a race condition..was a logic error.

airtime_mvc/application/models/Preference.php

@@ -38,6 +38,8 @@ class Application_Model_Preference
                 $paramMap[':id'] = $userId;
             }
 
+            Application_Common_Database::prepareAndExecute("LOCK TABLE cc_pref");
+
             $result = Application_Common_Database::prepareAndExecute($sql, 
                     $paramMap, 
                     Application_Common_Database::COLUMN,