Corrected wrong order of commands

[BakungaBronson]

In the notebook, under section 4.3.2, LangChain Q&A Retriever, the code block where we test chat history has two commands switched in order, resulting in an error while running. Switching to have the "query" variable set first fixes this issue.

What does this PR do?

This PR switches two lines of code, with one meant to run before the other. The

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Thanks for contributing 🎉!

[mreso]

Thanks for the contribution! LGTM