Description of problem:
Subscription validation fails for replication subscriptions which have been successfully saved.

Version-Release number of selected component (if applicable):
Reproduced on appliance build master-201605092000-994aa056f5

How reproducible:
Always

Steps to Reproduce:
Configure a remote region as a replication source
Configure a global region with a subscription pointing to the previously configured appliance
Refresh the Replication settings page
Attempt to validate the subscription

Actual results:
Validation failed with error: 'FATAL: password authentication failed for user "root"

Expected results:
Validation succeeds as this subscription was successfully saved and is currently replicating

Additional info:

This has to do with password handling.
The validation is done directly by the UI which doesn't have access to passwords of currently saved subscriptions. The validation will pass when the user enters the password when initially saving the subscription, but will fail once the subscription needs to be retrieved from the database.

I suggest moving the validation call out of the UI and into the PglogicalSubscription model which can then fetch the password from the database for the purposes of validation while still not saving it in the object as it does for updates.