_include: Do not initialize session unless it is needed.

git-svn-id: https://simplesamlphp.googlecode.com/svn/trunk@2191 44740490-163a-0410-bde0-09ae8108e29a

www/_include.php

@@ -91,9 +91,6 @@ if (!file_exists($configdir . '/config.php')) {
 	exit(1);
 }
 
-/* Make sure that the session is initialized before any output. */
-SimpleSAML_Session::getInstance();
-
 /* Set the timezone. */
 SimpleSAML_Utilities::initTimezone();