Implemented fix suggested in Issue 823 - Add DOCUMENT_ROOT to require_once path on domain edit [and contacts_vcard.php, and save_switch_xml() function].

contacts_vcard.php

@@ -199,7 +199,7 @@ if (count($_GET)>0) {
 			}
 
 			//include
-				require_once PROJECT_PATH."resources/qr/qrcode.php";
+				require_once $_SERVER["DOCUMENT_ROOT"].PROJECT_PATH."/resources/qr/qrcode.php";
 
 			//error correction level
 				//QR_ERROR_CORRECT_LEVEL_L : $e = 0;