XDCR does not handle with multiple RBAC users to the same target cluster

Background

User will want to have fine grade access control, where they have a user for each bucket replicated via XDCR even when the buckets happens to be on the same cluster

Problem

Cannot creating two XDCR replications to the the same cluster with different users. This is because the UI believe that there is already a replication setup:

Steps to reproduce

1. Setup two clusters.
2. On the source cluster use the beer-sample bucket
3. On the target create two buckets (beer-cache, brewery-cache)
4. On the target create two users(XDCR-beer, XDCR-brewery), each one have the replication role access to each bucket respectively
5. Add a XDCR cluster using the 1st user (XDCR-beer)
6. Add a XDCR cluster using the 2nd user (XDCR-brewery), at this point the error fails:

Workaround

Use one user and give them access to both buckets.