classes/package_deb: create .gz index instead of .bz2
apt is looking for Packages.gz files instead of the .bz2 files we are
currently creating and failing when they cannot be found. It is not
immediately obvious how to make the current version use the .bz2
indexes; thus create .gz indexes for now which allows us to
successfully create images.
Tested on both a Fedora 14 and an Ubuntu 11.10 host machine.
Fixes [YOCTO #1858].
Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
