[svn r15219] api_session_unregister function changed

http://www.php.net/session_unregister.
"This function does not unset the corresponding global variable for name , it only prevents the variable from being saved as part of the session. You must call unset()  to remove the corresponding global variable."

main/inc/lib/main_api.lib.php

@@ -754,12 +754,16 @@ function api_session_register($variable)
  */
 function api_session_unregister($variable)
 {
+	if(isset($GLOBALS[$variable]))
+	{
+		unset ($GLOBALS[$variable]);
+	}
+	
 	if(isset($_SESSION[$variable]))
 	{
-		session_unregister($variable);
 		$_SESSION[$variable] = null;
-	}
-	unset ($GLOBALS[$variable]);
+		session_unregister($variable);		
+	}	
 }
 /**
  * Clear the session