Update update-settings.asciidoc

[sandeepkanabar]

Corrected a small typo - 'cross restarts' to 'across restarts'

• Have you signed the contributor license agreement?
• Have you followed the contributor guidelines?
• If submitting code, have you built your formula locally prior to submission with gradle check?
• If submitting code, is your pull request against master? Unless there is a good reason otherwise, we prefer pull requests against master and will backport as needed.
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• If you are submitting this code for a class then read our policy for that.

[elasticmachine]

Since this is a community submitted pull request, a Jenkins build has not been kicked off automatically. Can an Elastic organization member please verify the contents of this patch and then kick off a build manually?

[cbuescher]

LGTM, thanks @sandeepkanabar