securedrop-admin does not include new UID in signature check

[eloquence]

Description

securedrop-admin (which is used by the graphical updater) does not check for our new release key UID, here:

https://github.com/freedomofpress/securedrop/blob/develop/admin/securedrop_admin/__init__.py#L946-L949

The new UID is [email protected]. This omission means that the tag verification will fail. (Note the closing quotation mark on the first line, which is not present when the key has a UID associated with it.)

Steps to Reproduce

A bit difficult as we currently don't have a tag signed with the new key up. I've so far only tested this by manually attempting to match signature output in the same manner as the updater does.