Fix issue with long meta and og description

Author: ihorvansach

Block/Post/View/Opengraph.php

@@ -48,7 +48,7 @@ public function getDescription()
         $content = trim($this->stripTags($this->getPost()->getContent()));
         $max = 300;
         if (mb_strlen($content) > $max) {
-            $content = mb_substr($content, $max);
+            $content = mb_substr($content, 0, $max);
         }
 
         return $content;

Model/Post.php

@@ -222,7 +222,7 @@ public function getMetaDescription()
 
         $desc = strip_tags($desc);
         if (mb_strlen($desc) > 160) {
-            $desc = mb_substr($desc, 160);
+            $desc = mb_substr($desc, 0, 160);
         }
 
         return $desc;