Stop the summarisation mechanism if the conversation consists of a single question:

[jrhender]

The idea is that the summary should never include the question which has just been asked (so if there's only been an initial question, there is NO summary).

Note: this issue was initially discovered by @mwatkins1970

[jrhender]

Branch with a possible fix from @watkins1970 for this issue: main...jrhender:stampy-chat:only-summarize-if-more-than-one-question . I think the relevant change is in the run_query function.