fix typo

Author: four4fish

pytorch_lightning/trainer/connectors/accelerator_connector.py

@@ -484,7 +484,7 @@ def _is_slurm_managing_tasks(self):
         return num_slurm_tasks == total_requested_devices
 
     def _choose_strategy(self):
-        if self._accelerator_flag == "ipu_strategy":
+        if self._accelerator_flag == "ipu":
             self._strategy_flag = "ipu_strategy"
         elif self._accelerator_flag == "tpu":
             if self._parallel_devices and len(self._parallel_devices) > 1: