pakfire.cgi: Bring back old logic for log displaying

pakfire.cgi: Bring back old logic for log displaying

Trying to get rid of the system backpipe check if a pakfire is running
does not work very well. It simply makes the code more complex and
only introduced some new problems.

This commit switches back to the old logic which worked well in the
past.

Signed-off-by: Stefan Schantl <stefan.schantl@ipfire.org>
Reviewed-by: Bernhard Bitsch <bbitsch@ipfire.org>
Tested-by: Bernhard Bitsch <bbitsch@ipfire.org>