fix replicate error

litellm/llms/replicate.py

@@ -24,7 +24,6 @@ def start_prediction(version_id, input_data, api_token, logging_obj):
     initial_prediction_data = {
         "version": version_id,
         "input": input_data,
-        "max_new_tokens": 500,
     }
 
         ## LOGGING
@@ -109,17 +108,32 @@ def completion(
     litellm_params=None,
     logger_fn=None,
 ):
-    # Convert messages to prompt
-    prompt = ""
-    for message in messages:
-        prompt += message["content"]
-
     # Start a prediction and get the prediction URL
     version_id = model_to_version_id(model)
-    input_data = {
-        "prompt": prompt,
-        **optional_params
-    }
+    if "meta/llama-2-13b-chat" in model: 
+        system_prompt = ""
+        prompt = "" 
+        for message in messages: 
+            if message["role"] == "system":
+                system_prompt = message["content"]
+            else: 
+                prompt += message["content"]
+        input_data = {
+            "system_prompt": system_prompt,
+            "prompt": prompt,
+            **optional_params
+        }
+    else:
+        # Convert messages to prompt
+        prompt = ""
+        for message in messages:
+            prompt += message["content"]
+
+        input_data = {
+            "prompt": prompt,
+            **optional_params
+        }
+
 
     ## COMPLETION CALL
     ## Replicate Compeltion calls have 2 steps