Redirect to the download page if the payload is invalid

uitwww/download.py

@@ -230,7 +230,7 @@ class Downloads:
             try:
                 content = signer.loads(payload)
             except itsdangerous.BadSignature:
-                flask.abort(400)
+                return flask.redirect(flask.url_for("pages.download_index"))
 
             return flask.render_template("download/thanks.html", **content)