Bug#833863: debian-installer: Unable to remove encrypted volume

[Bob Clough <bob.clough@codethink.co.uk>]

Package: debian-installer
Severity: normal
Tags: d-i

Dear Maintainer,

I came across a bug in d-i in jessie.  Once an encrypted volume has been
created and enabled, it cannot be removed without competely rebooting the
machine.

* Create an encrypted volume
* Notice you forgot to add a non-encrypted boot partition
* Exclaim "bugger"
* Attempt to delete the encrypted volume by selecting it and pressing return
  -> Nothing Happens
* Attempt to delete it by pressing the "Manage Encrypted Volumes" option
  -> Only options are "Create New Encrypted Volume" and "Finish"
* Attempt to directly delete the partition from the dish
  -> Get a red screen that tells you you're not allowed to edit the partiton
layout, as it has an encrypted volume on it.



-- System Information:
Debian Release: 8.5
  APT prefers stable-updates
  APT policy: (500, 'stable-updates'), (500, 'stable')
Architecture: amd64 (x86_64)

Kernel: Linux 3.16.0-4-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)