[cookienotice] Fix wrong type-hint in hook function cookienotice_page_end

- Fix "Argument 2 passed to cookienotice_page_end() must be of the type array, string given" error

cookienotice/cookienotice.php

@@ -98,7 +98,7 @@ function cookienotice_page_content_top(App $a, string &$b)
  *
  * @return void
  */
-function cookienotice_page_end(App $a, array &$b)
+function cookienotice_page_end(App $a, string &$b)
 {
 	$text = (string)DI::config()->get('cookienotice', 'text', DI::l10n()->t('This website uses cookies to recognize revisiting and logged in users. You accept the usage of these cookies by continue browsing this website.'));
 	$oktext = (string)DI::config()->get('cookienotice', 'oktext', DI::l10n()->t('OK'));