[enhancement request] multi-user support

[zosky]

problem statement

the service account has been autherized to access all users on our domain ... but i can not set delegationEmail in google.auth.JWT:L88

my hack

• changing L88 to this.key.doAsUser.
• added it to the key
• restarted NR

IT WORKED

it would be best if this could be set through the flow - but that seems out of reach with my current skill :)

this approach still requires 1 connection node per person (even though they all use the 1 service account). if you're interested in a pull request, i could try adding it as an optional field