Bug#931130: Document that local configuration for dummy and bonding modules are getting overwritten by systemd

[Justin B Rye]

Michael Biebl wrote:
> Afaiu, the kernel default is to create one dummy device by default when
> the module is loaded.
> I assume there might be cases where users rely on that default behaviour
> without having explicitly configured anything.

Do we have any idea what their use case would be?  Apparently a
different one from Baptiste's, if it's true that he needed to
explicitly configure "numdummies=1"...
 
> Atm, the release note entry reads like only admins who have a modprobe.d
> config are possibly affected.

That's true.  I can't immediately see any way of rephrasing it without
making it much more complicated.
-- 
JBR	with qualifications in linguistics, experience as a Debian
	sysadmin, and probably no clue about this particular package