FIX error when doing sed on non existing privoxy config file

[pubkey]

When doing a full build from the Dockerfile in the repo, I got this error because the RUN command tries to run sed on a file that does not exist.

This commit ensures that the privoxy config file exists, before working with it.

[skobkin]

Are you sure that this is a fix?

Because you'll get an empty config for privoxy this way. It fixes the build itself, but breaks the behavior of the original image.

[pubkey]

It works for me at least.
I mean, without the fix it does not even start up.
With the fix, it creates the file, and it still runs the following sed commands to fill it.

[skobkin]

With the fix, it creates the file, and it still runs the following sed commands to fill it.

They're not filling the file. Did you check it's content after the build?

/ # du -sh /etc/privoxy/config
0       /etc/privoxy/config
/ # cat /etc/privoxy/config | wc -m
0

[skobkin]

You can probably bring the old /etc/privoxy/config to the repository and add it using COPY. But you'll need to check that it works well first.

Currently the image will built successfully, but only Tor part of it will be working as intended. So there is no point in such changes, you can just use image which only contains Tor itself.

[skobkin]

This command just creates an empty file.

The following sed commands are doing nothing after that. So after this fix privoxy will not function as intended by the maintainer.