docs: minor docstring typo/grammar correction (influxdata#687)

Author: CloCkWeRX

influxdb_client/client/influxdb_client.py

@@ -265,15 +265,15 @@ def retry(self, conf: (str, str, str), data: str, exception: InfluxDBError):
 
         :param write_options: Write API configuration
         :param point_settings: settings to store default tags
-        :key success_callback: The callable ``callback`` to run after successfully writen a batch.
+        :key success_callback: The callable ``callback`` to run after having successfully written a batch.
 
                                The callable must accept two arguments:
                                     - `Tuple`: ``(bucket, organization, precision)``
                                     - `str`: written data
 
                                **[batching mode]**
 
-        :key error_callback: The callable ``callback`` to run after unsuccessfully writen a batch.
+        :key error_callback: The callable ``callback`` to run after having unsuccessfully written a batch.
 
                              The callable must accept three arguments:
                                 - `Tuple`: ``(bucket, organization, precision)``