added variable to bootstrap via docker

config.sh.template

@@ -14,4 +14,5 @@ netDNS2="198.51.100.10"
 netNTP="pool.ntp.org"
 pwdAdmin=""                         # "" blank for auto-generation
 pwdRoot=""                          # "" blank for auto-generation
+debootstrap="native"                # docker, to run in docker container
 extraPackages="qemu-guest-agent"    # additional packages to install, e.g. cryptsetup