start: move env setup before container setup
start: move env setup before container setup

The hooks (e.g. lxc.hook.mount) should have the environment variables the user
gave us available.

Signed-off-by: Christian Brauner <48455ab3070520a2d174545c7239d6d0fabd9a83@ubuntu.com>

terceiro/lxc,ss1h2a3tw/lxc,caglar10ur/lxc,hallyn/lxc,thmo/lxc,hallyn/lxc,hallyn/lxc,caglar10ur/lxc,caglar10ur/lxc,thmo/lxc,terceiro/lxc,thmo/lxc,ss1h2a3tw/lxc,terceiro/lxc,ss1h2a3tw/lxc