Allow manifest loading via CSP (2)

lib/Configuration.php

@@ -51,7 +51,7 @@ class Configuration
             'languagedefault' => '',
             'urlshortener' => '',
             'icon' => 'identicon',
-            'cspheader' => 'default-src \'none\'; connect-src *; script-src \'self\'; style-src \'self\'; font-src \'self\'; img-src \'self\' data:;',
+            'cspheader' => 'default-src \'none\'; connect-src *; manifest-src \'self\'; script-src \'self\'; style-src \'self\'; font-src \'self\'; img-src \'self\' data:;',
             'zerobincompatibility' => false,
         ),
         'expire' => array(