import sets incorrect tree path if arch is specified

Binary package hint: cobbler

When importing and specifying the arch, the tree patch is set incorrectly. The import command looks like:

cobbler import --name=amd64-arch-specified --path=/mnt --breed=ubuntu --arch=x86_64

and the tree created is:

amd64-arch-specified-x86_64

However, the tree path is set incorrectly, like:
tree=http://@@http_server@@/cblr/ks_mirror/amd64-arch-specified

when the following should be the correct:
tree=http://@@http_server@@/cblr/ks_mirror/amd64-arch-specified-x86_64
.

This was discovered when trying to deploy the imported ISO through koan:

sudo koan --virt --server=192.168.1.118 --profile=amd64-arch-specified-x86_64 --virt-name=test1-arch --virt-bridge=virbr0
- looking for Cobbler at http://192.168.1.118/cobbler_api
install_tree: http://192.168.1.118/cblr/ks_mirror/amd64-arch-specified
- using qemu hypervisor, type=kvm
Mon, 25 Apr 2011 15:58:43 DEBUG No conn passed to Guest, opening URI 'qemu:///system'
Mon, 25 Apr 2011 15:58:44 DEBUG DistroInstaller location is a network source.
libvir: QEMU error : Domain not found: no domain with matching name 'test1-arch'
- adding disk: /var/lib/libvirt/images//test1-arch-disk0 of size 5
Mon, 25 Apr 2011 15:58:44 WARNING The filesystem will not have enough free space to fully allocate the sparse file when the guest is running. 5120 M requested > 4504 M available
Mon, 25 Apr 2011 15:58:44 DEBUG HTTP hasFile: didn't find http://192.168.1.118/cblr/ks_mirror/amd64-arch-specified/
<type 'exceptions.ValueError'>
Invalid install location: Opening URL http://192.168.1.118/cblr/ks_mirror/amd64-arch-specified/ failed.