When a self-hosted Zulip server does a data export and then import
process into a different hosting environment (i.e. not sharing the
RemoteZulipServer with the original, we'll have various things that
fail where we look up the RemoteRealm by UUID and find it but the
RemoteZulipServer it is associated with is the wrong one.
Right now, we ask user to contact support via an error page but
might develop UI to help user do the migration directly.
Aman Agrawal