* fix(mongodb): merge URI auth fields with username/password override
SetAuth replaced the whole Credential parsed from the URI, dropping
AuthSource and AuthMechanism. Start from the URI-parsed Auth and only
override the username and password so credentials scoped to a specific
auth database keep working.
* fix(mongodb): set PasswordSet for explicit credentials
Required by GSSAPI auth when a password is supplied; ignored for other
mechanisms.
Chris LuandGitHub
7aba10fa1a