ID 268377 - PYTHONPATH/PYTHONHOME environment variable are not ignored in safer mode

PYTHONPATH/PYTHONHOME environment variable are not ignored in safer mode 

Customer reported version

3.0v2

Customer reported platform
fedora

Steps to reproduce

1) Set the environment variables PYTHONPATH/PYTHONHOME to point to a different location 

2) Try launching Mari in safer mode

result: safer mode in Mari is not ignoring the environment variables PYTHONPATH/PYTHONHOME

Expected behaviour
PYTHONPATH/PYTHONHOME environment variables to be ignored if the user launches Mari in safer mode

Actual behaviour
PYTHONPATH/PYTHONHOME environment variables are not ignored in safer mode

Workaround
Unknown.

Reproduced by Manual QA