Bug#927395: Do not touch(1) update-exim4.conf.conf for no good reason

[積丹尼 Dan Jacobson]

retitle 927395 Add a update-exim4.conf.conf.local to avoid edit conflicts
thanks

Well all I know is
/etc/exim4/exim4.conf.localmacros
is the safe place for macros, so there also should be a safe place for
things that would go in
/etc/exim4/update-exim4.conf.conf too.

By safe I mean guaranteed that you and I are not trying to edit the same
file.

I mean the package generates lots of files, some with warnings "DO NOT
EDIT, autogenerated", some with warnings "automatic changes to this file
may happen".

Well, certainly you could be so kind as your are with
/etc/exim4/update-exim4.conf.localmacros by just reading an additional
file in if found.

That's the whole idea behind the ...d/* where we could just drop in a
./000_my_stuff , but alas all there is is just a monolithic
/etc/exim4/update-exim4.conf.conf .