Working directory is not updated when switching from debug/release with qbs

When using a QBS project, in project's settings the executable is correctly set by Qt Creator. However, the working directory is set once and never updated.

To reproduce:

• Create a simple QBS projet
• Starts in Debug mode
• Switch to release
• Starts in Release mode

If you go to projet's settings, you will see that the working directory is still the debug one, so you are starting the release .exe from the debug directory.

This can lead to problems when loading dlls/plugins from current directory.