Avoid permissions errors for chown .well-known

[kevinoid]

When acme.sh is run as a non-root user different from the owner of the webroot directory it is unable to change the owner of the files in .well-known to that user, causing permissions errors. Avoid this by making the files world-readable.

These files should pose no disclosure risk since they are sent in cleartext during the HTTP Identifier Validation Challenge and may already be exposed by directory enumeration, depending on server settings. AFAIK they should be safe to expose as world-readable in all cases.

Fixes Neilpang/acme.sh#32

Thanks for considering, Kevin

[kevinoid]

For reference, it does not appear that the issue was fixed. I'm open to providing an alternative implementation if this one was found to be unacceptable.

[Neilpang]

sorry, it was closed by accident.