ctrl: Do not query only for keys in Invitation
ctrl: Do not query only for keys in Invitation

In case the user already exists, we would try to access an index
out of range, because KeysOnly leaves our slice of Users untouched.

coduno/api,flowlo/coduno-api,pbochis/api,flowlo/coduno-api,pbochis/api,coduno/api,flowlo/coduno-api,pbochis/api,coduno/api