Server auto-selects the bucket using username

The server must not automatically select bucket for SDK, which supports SELECT_BUCKET command (and announce it in HELLO flags).

Build 6.5.0-4380 uses username to automatically select the bucket and sends bucket configuration instead of more bucket-less.

In test scenario, the cluster has bucket named "default", and the user named "default" with password "password". Also it has account "Administrator" with password "password".

Expected behaviour: regardless the username it must always send bucket-less configuration if SDK does not send SELECT_BUCKET.
Actual behaviour: it sends bucket configuration for user "default" and bucket-less config for "Administrator". See attached dumps