Previously, the email mirror queue worker used the API bindings to send
messages to Zulip, as if it were any other API client.
This is inefficient since we're running the worker inside the Django
context on a machine with database access; we can instead just use the
internal message-sending functions we use elsewhere. This also resolves
potential issues with SSL certificates, etc. that might occur when we
were previously making a HTTPS connection.
(imported from commit 6de8015829bec440f1af0199a2138828e86ed2a4)
Here, we don't want to check the uploading users' realm when determining
message privacy, because that'll prevent non-Zulip users from having
email-mirror-uploaded images. Instead, we just pass along the target
realm for the message explicitly to upload_message_image()
(imported from commit 6891261552135b1f41ff9da55ffe963ee5000556)
Luke Faraone
Tim Abbott