Bug#473461: #473461 should use dpkg --no-triggers

[Felix Zielcke <fzielcke@z-51.de>]

Please consider the wishlist bug against grub2 for implementing a
trigger (481542) before implementing this in apt.

Currently update-grub, which generates menu.lst/grub.cfg, gets called on
a kernel removal, a kernel install and on grub update itself.
As you can see in the report with current sid apt/dpkg the man-db
trigger gets called after everything is extracted but before the
packages are configured.
This would be fine for grub too.

But if this gets changed and we can't rely that our trigger gets called
after extracting everything then it might be that update-grub doestn't
ever get called if the whole apt/dpkg configure run fails at some point
and then you probable have only a not anymore installed kernel in the
grub menu.