Fix Content-type of downloaded results

owl.py

@@ -968,7 +968,7 @@ def export_points(format):
 
         enc = JSONEncoder(ensure_ascii=False, sort_keys=True, indent=4)
         resp = make_response(enc.encode(out))
-        resp.headers.add('Content-type', 'application/json')
+        resp.mimetype = 'application/json'
         return resp
     elif format == "csv":
         out = io.StringIO()
@@ -982,7 +982,8 @@ def export_points(format):
                 sum(points[s.uid].values()),
             ] + [points[s.uid].get(t.ident, "") for t in topics])
         resp = make_response(out.getvalue())
-        resp.headers.add('Content-type', 'text/csv; charset=utf-8')
+        resp.mimetype = 'text/csv'
+        resp.mimetype_params['charset'] = 'utf-8'
         return resp
     else:
         raise NotImplementedError()