Merge pull request boxcutter#39 from frntn/patch-1

Remove duplicate in preseed.cfg

Author: annawake

http/preseed.cfg

@@ -29,7 +29,6 @@ d-i partman-auto-lvm/guided_size string max
 d-i partman-auto/choose_recipe select atomic
 d-i partman-auto/method string lvm
 d-i partman-lvm/confirm boolean true
-d-i partman-lvm/confirm boolean true
 d-i partman-lvm/confirm_nooverwrite boolean true
 d-i partman-lvm/device_remove_lvm boolean true
 d-i partman/choose_partition select finish