Update PageRepo.php

Fix encoding problem.

By default DOMDocument::loadHTML treats a string as being encoded with ISO-8859-1. This causes a problem with saving cyrillic pages' text that becomes completely unreadable (like Проверка instead of normal symbols).

@@ -125,7 +125,7 @@ class PageRepo
         if($htmlText == '') return $htmlText;
         libxml_use_internal_errors(true);
         $doc = new \DOMDocument();
-        $doc->loadHTML($htmlText);
+        $doc->loadHTML(mb_convert_encoding($htmlText, 'HTML-ENTITIES', 'UTF-8'));
 
         $container = $doc->documentElement;
         $body = $container->childNodes->item(0);
@@ -359,4 +359,4 @@ class PageRepo
     }
 
 
-}
\ No newline at end of file
+}