Remove debconf-apt-progress usage
Remove debconf-apt-progress usage

debconf-apt-progress is a tool to show a whiptail based dialog with progress bar for apt package installs, but it is some downsides:
- It aborts whenever apt or debconf halt for an interactive input, hence this would need to be prevented carefully, e.g. via "DEBIAN_FRONTEND=noninteractive" and "--force-confdef/old/new/miss", while it is questionable whether PiVPN should mute such configuration inputs for users.
- It even aborts when such interactive input is not actually required in some cases, but triggered by some other debconf load internals: pivpn#1360

Most importantly, aside of the visually probably appealing progress bar, debconf-apt-progress has not any upsides but reduces transparency of what is actually done, and the installer has a fallback already.

This commit removes the debconf-apt-progress usage in favour of the fallback: direct apt-get usage.

Signed-off-by: MichaIng <5f726662e7ca541c0aec63efdec81c7c2711727a@dietpi.com>
pivpn/pivpn