"Make" build steps are not being updated when environment changes

1. Make sure that you don't have a path to mingw32-make.exe in your PATH environment variable.
2. Open a project and configure it to use a Qt version built with MinGW.
3. Try to build the project.
   Building fails because Creator can't find mingw32-make.
4. Go to Projects mode.
   In "Build Steps" and "Clean Steps" you can read "mingw32-make not found in the environment".
5. In "Build Environment", add the path to mingw32-make.exe to your PATH environment variable.
   In "Build Steps" and "Clean Steps" you can still read "mingw32-make not found in the environment".
6. Try to build the project.
   The project can be built so mingw32-make must have been found.
7. Close and reopen the project.
8. Go to Projects mode.
   In "Build Steps" and "Clean Steps" you can now read the actual path to mingw32-make.exe.

These labels should be updated when the environment changes.