For modular tags we only include packages that are included in the
module. Originally the filter was taking package names from
rpms.artifacts section of MMD.
This however does not work correctly, as there can easily be module
which lists foo.src but does not want to include foo.x86_64 or other
arches.
This patch fixes this particular problem by included arch in the set of
packages to be kept.
JIRA: COMPOSE-3543
Signed-off-by: Lubomír Sedlář <lsedlar@redhat.com>