Remove possibly incorrect default mention

What does this MR do?

This is not the case for any of my docker executor Runners. I did a complete fresh install to verify as well, the setting is not enabled by default after registering a new Runner with docker executor. I can't verify it for kubernetes, but given that the defaults are also mentioned in the linked advanced Runner config, I'd say we remove the duplicate information here even if the latter half might be correct.

Related issues

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