fix exception where openrouter doesn't populate - no longer index without fallback

backend/open_webui/utils/middleware.py

@@ -795,7 +795,7 @@ async def process_chat_payload(request, form_data, metadata, user, model):
 
         # Workaround for Ollama 2.0+ system prompt issue
         # TODO: replace with add_or_update_system_message
-        if model["owned_by"] == "ollama":
+        if model.get("owned_by") == "ollama":
             form_data["messages"] = prepend_to_first_user_message_content(
                 rag_template(
                     request.app.state.config.RAG_TEMPLATE, context_string, prompt