Warning when disabling default archive_sites

[ryandesign (Ryan Carsten Schmidt)]

archive_sites.conf says:

# To disable the default archive source, uncomment the following dummy
# entry; it will shadow the one from the ports tree.
#name                	macports_archives

But if I do that, then when I use MacPorts, I get this warning:

Warning: archive_sites.conf: no urls set for macports_archives