[Improvement] fix discourse loader to avoid rate limit (#953)

Co-authored-by: Deven Patel <deven298@yahoo.com>

embedchain/loaders/youtube_video.py

@@ -19,7 +19,7 @@ class YoutubeVideoLoader(BaseLoader):
         doc = loader.load()
         output = []
         if not len(doc):
-            raise ValueError("No data found")
+            raise ValueError(f"No data found for url: {url}")
         content = doc[0].page_content
         content = clean_string(content)
         meta_data = doc[0].metadata