* fix(updater): warn when the update download URL is not https
`validate_endpoints` enforces `https` for the endpoints, but not for the `url`
of the manifest, so the artifact can be downloaded in plaintext. Enforcing it
would break existing releases (left for v3); `Update::download` now logs a
warning instead, unless `dangerousInsecureTransportProtocol` is enabled.
plugins/updater/src/updater.rs
* Apply suggestion from @lucasfernog