Some popular artifact caches (e.g. Artifactory) do not provide HTTP
CONNECT endpoints and thus aren't supported by es_proxy_host and
es_proxy_port. This patch templates out the scheme and authority
components (i.e. "https://artifacts.elastic.co" ) of the apt and
yum repo URLs to accommodate the use of such artifact caches.
Previously, each of the calls generated a warning : "Using tests as
filters is deprecated. Instead of using `result|version_compare` use
`result is version_compare`. This feature will be removed in version
2.9.".