[booru] prevent crash when file URL is empty (#5859)

- catch all exceptions, including IndexError,  and not just a select few
- change logging message level to  warning

gallery_dl/extractor/booru.py

@@ -36,9 +36,10 @@ class BooruExtractor(BaseExtractor):
                 url = self._file_url(post)
                 if url[0] == "/":
                     url = self.root + url
-            except (KeyError, TypeError):
-                self.log.debug("Unable to fetch download URL for post %s "
-                               "(md5: %s)", post.get("id"), post.get("md5"))
+            except Exception as exc:
+                self.log.debug("%s: %s", exc.__class__.__name__, exc)
+                self.log.warning("Unable to fetch download URL for post %s "
+                                 "(md5: %s)", post.get("id"), post.get("md5"))
                 continue
 
             if fetch_html: