Clarify that server names are at least 1 character
Fixes
@@ -45,7 +45,7 @@ following grammar::
IPv6char = DIGIT / %x41-46 / %x61-66 / ":" / "."
; 0-9, A-F, a-f, :, .
- dns-name = *255dns-char
+ dns-name = 1*255dns-char
dns-char = DIGIT / ALPHA / "-" / "."
