Revert changes

#564 has proven to be enough to accomodate Windows installs

lib/_autoload.php

@@ -8,15 +8,13 @@
  * @package SimpleSAMLphp
  */
 
+// SSP is loaded as a separate project
 if (file_exists(dirname(dirname(__FILE__)).'/vendor/autoload.php')) {
-    // SSP is loaded as a separate project
     require_once dirname(dirname(__FILE__)).'/vendor/autoload.php';
-} else if (file_exists(dirname(dirname(__FILE__)).'/../../autoload.php')) {
-    // SSP is loaded as a library
-    require_once dirname(dirname(__FILE__)).'/../../autoload.php';
-} else if (file_exists('/../../autoload.php')) {
-    // Windows version
-    require_once '/../../autoload.php';
-} else {
-    throw new Exception('Unable to load Composer autoloader');
+} else {  // SSP is loaded as a library
+    if (file_exists(dirname(dirname(__FILE__)).'/../../autoload.php')) {
+        require_once dirname(dirname(__FILE__)).'/../../autoload.php';
+    } else {
+        throw new Exception('Unable to load Composer autoloader');
+    }
 }