raise a RateLimitError when Twitter returns HTTP status 429

src/apiutils.nim

@@ -76,6 +76,9 @@ template fetchImpl(result, additional_headers, fetchBody) {.dirty.} =
       if resp.status == "401 Unauthorized" and result.len == 0:
         getContent()
 
+    if resp.status == $Http429:
+      raise rateLimitError()
+
     if resp.status == $Http503:
       badClient = true
       raise newException(InternalError, result)