minor #1344 change rfc reference for reserved top level dns names

[mnacharov]

RFC 7686 covers only .onion domain.

RFC 2606 covers four others:

• test
• example
• invalid
• localhost

Why example and localhost not set empty by default?

P.S.: issue link #1344 was taken from historical commit, where this comment was specified

[ralphdolmans]

I think RFC6761 is the one that should be referenced. That document specifies that example. should be resolved normally.

localhost. should give back the loopback addresses when queried for address types, which Unbound does:

unbound/services/localzone.c

Line 765 in 0feee99

/* localhost. zone */

test. and invalid. should generate negative responses.

I will update the RFC references in the code to RFC6761.

[ralphdolmans]

Thanks!