Fix man-db installation

[LoveMHz]

Fixed qemu-user crash with man-db with a proper workaround

[LoveMHz]

Not permanent, but hopefully enough to get the initial setup completed. Though, it might not be a bad idea to set it globally.

One more commit to the patching incoming. Testing.

[cmsj]

At the very least it would also need to be set for the large apt-get install command, since that is where the mandb process was handing.

I agree that the environment variable is a better workaround than mine, but mine at least has the advantage that it applies to any/all commands run in the chroot until the symlink is removed at the end of the script.