[Samba] Migration from samba_dsdb to tdbsam.

[Dewayne Geraghty]

While trying to resolve the loss of prefix for full_audit, I attempted to
update from Samba 4.3.9 to 4.4.5.  Its a very simple environment,
standalone server running on i386 built from source.

After performing the build and installation, I was informed that
passdb backend = samba_dsdb
was no longer supported, so I commented out the line, to find which default
I should use.  testparm advises it should be:
passdb backend = tdbsam

Is there a mechanism/tool to convert the backend samba_dsdb to tdbsam?

Regards, Dewayne.