fix(developer): upgrade removes preferences
fix(developer): upgrade removes preferences

The uninstall is supposed to remove HKCU settings for developer. However
a side-effect is that an upgrade (which msi treats as uninstall/
install internally) also removes HKCU settings. This is sad and it is
probably better overall to leave a dangling HKCU key after uninstall.

Fixes #2667.

tavultesoft/keymanweb,tavultesoft/keymanweb