fix infinite redirect during setup for windows hosts

lib/base.php

@@ -124,7 +124,7 @@ class OC{
 		// calculate the documentroot
 		$DOCUMENTROOT=realpath($_SERVER['DOCUMENT_ROOT']);
 		OC::$SERVERROOT=str_replace("\\",'/',substr(__FILE__,0,-13));
-		OC::$SUBURI=substr(realpath($_SERVER["SCRIPT_FILENAME"]),strlen(OC::$SERVERROOT));
+		OC::$SUBURI= str_replace("\\","/",substr(realpath($_SERVER["SCRIPT_FILENAME"]),strlen(OC::$SERVERROOT)));
 		$scriptName=$_SERVER["SCRIPT_NAME"];
 		if(substr($scriptName,-1)=='/'){
 			$scriptName.='index.php';