lxd/main_init_interactive: only ask for server host name when no joining token was provided
lxd/main_init_interactive: only ask for server host name when no joining token was provided

Signed-off-by: Jianming Ma <840d16f343d8e6d92a3b3ddc451c32d167b45bf9@hotmail.com>

atxwebs/lxd,lxc/lxd,lxc/lxd,stgraber/lxd,lxc/lxd,stgraber/lxd,lxc/lxd,lxc/lxd,atxwebs/lxd,lxc/lxd,lxc/lxd,hallyn/lxd,stgraber/lxd,stgraber/lxd,hallyn/lxd,stgraber/lxd,hallyn/lxd,hallyn/lxd,atxwebs/lxd,atxwebs/lxd,stgraber/lxd,stgraber/lxd,hallyn/lxd,hallyn/lxd