metadata: ignore old incompatible python-xattr module; we need python-pyxattr.
metadata: ignore old incompatible python-xattr module; we need python-pyxattr.

Signed-off-by: Avery Pennarun <e03ccfb89d416c4697ad6970ce86a92c1c28a78e@gmail.com>

apenwarr/bup,gevaerts/bup,ToxicFrog/bup,mhoeher/bup,gevaerts/bup,mhoeher/bup,tjanez/bup,jbaber/bup,gevaerts/bup,pombredanne/bup,pombredanne/bup,mhoeher/bup,gevaerts/bup,jbaber/bup,mhoeher/bup,jbaber/bup,tjanez/bup,pombredanne/bup,jbaber/bup,pombredanne/bup,tjanez/bup,pombredanne/bup,mhoeher/bup,jbaber/bup,ToxicFrog/bup,pombredanne/bup,tjanez/bup,mhoeher/bup,gevaerts/bup,tjanez/bup,apenwarr/bup,ToxicFrog/bup,tjanez/bup,jbaber/bup,ToxicFrog/bup,apenwarr/bup,apenwarr/bup,ToxicFrog/bup