Fix Linux.md

[Mon-ius]

The original document was too misleading which caused unnecessary trouble. Here I provided a more safe way to prevent the unexpecting conditions. Hope you CF guy can take it into consideration, cheers :)

[haleycode]

Thank you for the suggestion! We won't be updating the docs at this time. The instructions on the following page should be helpful: https://developers.cloudflare.com/cloudflare-one/connections/connect-devices/warp/deployment/manual-deployment/#linux

[Mon-ius]

I don't mean to be unfriendly, but according to your answer, it's not related to what I reported at all. If you don't understand how your guide can misleading people, you can report it to your supervisor, young boy :)