Support real-time piping as non-root user
Support real-time piping as non-root user

If running as a user that can't open a terminal, it's still important to set the
pipe as non-blocking. Otherwise parsing never finishes, making goaccess
unusable.

Fixes #868.

allinurl/goaccess,allinurl/goaccess,allinurl/goaccess,allinurl/goaccess