resilient_requests: replace method_whitelist

* method_whitelist was deprecated in urllib3 v1.26.0 and removed in v2.

hepdata_cli/resilient_requests.py

@@ -43,7 +43,7 @@ def send(self, request, **kwargs):
 retry_strategy = Retry(total=TOTAL_RETRIES,
                        backoff_factor=2,
                        status_forcelist=[429, 500, 502, 503, 504],
-                       method_whitelist=["GET", "POST"])
+                       allowed_methods=["GET", "POST"])
 adapter = TimeoutHTTPAdapter(max_retries=retry_strategy)