[youporn] Fix: Add encrypted link to links array only if not already in it

youtube_dl/extractor/youporn.py

@@ -65,6 +65,7 @@ class YouPornIE(InfoExtractor):
         encrypted_links = re.findall(r'page_params.encryptedQuality[0-9]{3,4}URL\s=\s\'([a-zA-Z0-9+/]+={0,2})\';', webpage)
         for encrypted_link in encrypted_links:
             link = aes_decrypt_text(encrypted_link, video_title, 32).decode('utf-8')
+            # it's unclear if encryted links still differ from normal ones, so only include in links array if it's unique
             if link not in links:
                 links.append(link)