prevent flake8 errors from comments looking like type annotations

gallery_dl/extractor/tumblr.py

@@ -108,11 +108,11 @@ class TumblrExtractor(Extractor):
                     del photo["alt_sizes"]
                     yield self._prepare_image(photo["url"], post)
 
-            url = post.get("audio_url")  # type: "audio"
+            url = post.get("audio_url")  # type "audio"
             if url and url.startswith("https://a.tumblr.com/"):
                 yield self._prepare(url, post)
 
-            url = post.get("video_url")  # type: "video"
+            url = post.get("video_url")  # type "video"
             if url:
                 yield self._prepare(_original_video(url), post)