nginx.md: Add note about potential security isues 
nginx.md: Add note about potential security isues 

I thought about this while setting this up, and then found this guide (I was setting it up without the guide first.)

The potential security implications are important, so I think we should mention them here on this web page. (We could even go further by outright _warning_ people about this, but perhaps letting people know about it so they can make an informed decision is a better way to go. This can be perfectly fine for certain intranet scenarios.)
thaJeztah/distribution,thaJeztah/distribution