ceph-client: fix copy of python modules
ceph-client: fix copy of python modules

the site-packages content was wrongly copied, causing a
.../site-packages/site-packages/... in the ceph-client packages.
This renders thi ceph tool unusable.

NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs