Comment 2 for bug 1667725

Even though it won't be possible to make the API in question reliable in the short term, I'm persuaded that this is worth doing for a couple of reasons:

 * it will allow reducing the necessary egress firewall configuration for systems on locked-down networks to use add-apt-repository
 * it will help us to transition to updating keyservers on a best-effort basis, and keeping key material in the Launchpad database (we haven't committed to doing this, but given recent keyserver troubles it may be worth it)