httpd: Fix commit count in repo stats in history route

Instead of using always the repo HEAD for the commit count with
`repo::stats` we should use `repo::stats_from` and pass the `parent`
commit.

This way we allow e.g. a commit history for a peer with lesser commits
to be counted correctly.

Signed-off-by: Sebastian Martinez <me@sebastinez.dev>

radicle-httpd/src/api/v1/projects.rs

@@ -206,7 +206,7 @@ async fn history_handler(
 
     let response = json!({
         "commits": commits,
-        "stats":  repo.stats()?,
+        "stats":  repo.stats_from(&sha)?,
     });
 
     Ok::<_, Error>((StatusCode::OK, Json(response)))