Summary:
When connection manager is enabled pg listens on port 6433.

Fixed a bug in `SetProxyAddresses`, where the check for conflicting pg port was incorrect.

Fixes #26495
Jira: DB-15862

Test Plan: Manually tested with YBA universe

Reviewers: fizaa, telgersma, arybochkin, skumar

Reviewed By: telgersma

Subscribers: ybase, yql

Differential Revision: https://phorge.dev.yugabyte.com/D42709