two paragraphs are defined about the mirror option, removed the paragraph
having the older cli structure.
(cherry picked from commit c7d52cf762def52fecf9d1ec08dff61032dabd86)
Replace links to the phabricator site from https://phabricator.vyos.net to
https://vyos.dev
(cherry picked from commit 27512c94e62ec1883aafc97abafbd09d69ef1896)