Fix rounding of /repository/file retry-after value

Author: dsotirho-ucsc

src/azul/service/repository_controller.py

@@ -4,6 +4,9 @@
 )
 import json
 import logging
+from math import (
+    ceil,
+)
 from typing import (
     Any,
     Callable,
@@ -273,7 +276,7 @@ def download_file(self,
                     pass
                 elif wait == '1':
                     time_slept = self.server_side_sleep(float(retry_after))
-                    retry_after = round(retry_after - time_slept)
+                    retry_after = ceil(retry_after - time_slept)
                 else:
                     assert False, wait
             query_params = self._file_to_request(download.file) | adict(