[instagram] make accessing 'like_count' non-fatal (#5218)

gallery_dl/extractor/instagram.py

@@ -165,7 +165,7 @@ def _parse_post_rest(self, post):
             data = {
                 "post_id" : post["pk"],
                 "post_shortcode": post["code"],
-                "likes": post["like_count"],
+                "likes": post.get("like_count"),
                 "pinned": post.get("timeline_pinned_user_ids", ()),
                 "date": text.parse_timestamp(post.get("taken_at")),
             }