QWT handling - do not override explicit negative settings either
QWT handling - do not override explicit negative settings either

Do not override settings that user set to false/empty explicitly (like,
explicitly disabling audio emulation for give Windows VM). For this
reason, compare against None, not just any value that is false in
python.

QubesOS/qubes-core-admin,QubesOS/qubes-core-admin,QubesOS/qubes-core-admin