Update convert.py

convert.py

@@ -190,7 +190,12 @@ def previous_pr(api: "HfApi", model_id: str, pr_title: str) -> Optional["Discuss
     except Exception:
         return None
     for discussion in discussions:
-        if discussion.status == "open" and discussion.is_pull_request and discussion.title == pr_title:
+        if (
+            discussion.status == "open"
+            and discussion.is_pull_request
+            and discussion.title == pr_title
+            and discussion.target_branch == "main"
+        ):
             return discussion