chore: remove useless code (#8198)

api/core/model_runtime/model_providers/azure_openai/llm/llm.py

@@ -420,7 +420,7 @@ class AzureOpenAILargeLanguageModel(_CommonAzureOpenAI, LargeLanguageModel):
                 ),
             )
 
-            index += 0
+            index += 1
 
         # calculate num tokens
         prompt_tokens = self._num_tokens_from_messages(credentials, prompt_messages, tools)