Another bit of themes during upgrade

Signed-off-by: emanuele <[email protected]>

other/upgrade.php

@@ -616,8 +616,8 @@ if (isset($_GET['data']))
 	$support_js = $upcontext['upgrade_status']['js'];
 
 	// Load the language.
-	if (file_exists($boarddir . '/Themes/default/languages/Install.' . $upcontext['language'] . '.php'))
-		require_once($boarddir . '/Themes/default/languages/Install.' . $upcontext['language'] . '.php');
+	if (file_exists($modSettings['theme_dir'] . '/languages/Install.' . $upcontext['language'] . '.php'))
+		require_once($modSettings['theme_dir'] . '/languages/Install.' . $upcontext['language'] . '.php');
 }
 // Set the defaults.
 else