Fix Headline Hierarchy for Subsections of Slow query log

[Johnson145]

The sections Applicable versions etc. following the Slow query log paragraph refer to the latter only. Thus, they should be nested below it, but are shown on the same level right now.

PS: I hope it's okay that I'm creating an issue for this detail. If I got time, I may provide a PR later on. Just didn't want to forget sharing this information.