fix: simple_summary_wrapper function_call KeyError

[djkazic]

Fixes #1261

How to test
Use ollama and the default dolphin model and spam the chat until it hits the context window limit and an automatic /summarize is triggered. Alternatively, just use /summarize.

Have you tested this PR?
Yes

Is your PR over 500 lines of code?
No

[madgrizzle]

Is there a way to update this so that checks are successful? This fix works for me and summarize is otherwise broken.