latest release 0.19.6 included a polkit check.
this check is failing in some setups, leading to an unusable experience.
I'm temporarily disabling the check to be able to have an usable release
until we can debug what's causing the issue.

- Related: #152

Before finishing the main thread let's wait for the finish of the
bitmask/pid/... tear down. So the firewall gets down when you ctrl-c.

- Resolves: #142

- Resolves: #141