Pristine tar 4.11.6

Hi there,

Ubuntu's feature freeze is approaching, and I would like to update samba to 4.11.6. Since this is a dfsg tarball, It would be best for us to use the same one, so I prepared this pristine-tar branch following the instructions in d/README.source, and this is what I came up with.

The sha256sum is:

$ pristine-tar checkout samba_4.11.6+dfsg.orig.tar.xz
pristine-tar: successfully generated samba_4.11.6+dfsg.orig.tar.xz

$ sha256sum samba_4.11.6+dfsg.orig.tar.xz
5e270d46cf79db1bfb3155d207291ea05b8b7d7094d7eef13317b9a5cc2e33d5  samba_4.11.6+dfsg.orig.tar.xz