fix: correct role for system_message in AppendConversationResponse

The system_message was incorrectly being appended with role 'assistant'
instead of 'system'. This fixes the conversation history formatting
when a system message is provided.

Author: Haf-82

openai_components.py

@@ -705,7 +705,7 @@ def execute(self, ctx) -> None:
         ret = self.conversation.value
 
         if self.system_message.value is not None:
-            ret = ret + [{ 'role': 'assistant', 'content': self.assistant_message.value}]
+            ret = ret + [{ 'role': 'system', 'content': self.system_message.value}]
 
         if self.assistant_message.value is not None:
             ret = ret + [{ 'role': 'assistant', 'content': self.assistant_message.value}]