Made 429 Too Many Request HTTP error in `raw_call()` of `client.py` retryable (#337)

made 429 Too Many Request HTTP error in raw_call() retryable

mwclient/client.py

@@ -501,7 +501,10 @@ class Site:
                     # fall through to the sleep
                 elif stream.status_code == 200:
                     return stream.text
-                elif stream.status_code < 500 or stream.status_code > 599:
+                elif (
+                    (stream.status_code < 500 or stream.status_code > 599)
+                    and stream.status_code != 429  # 429 Too Many Requests is retryable
+                ):
                     stream.raise_for_status()
                 else:
                     if not retry_on_error: