fix: openllm completion start with prompt, remove it (#1303)

api/core/third_party/langchain/llms/openllm.py

@@ -66,6 +66,7 @@ class OpenLLM(LLM):
 
         json_response = response.json()
         completion = json_response["responses"][0]
+        completion = completion.lstrip(prompt)
 
         if stop is not None:
             completion = enforce_stop_tokens(completion, stop)