[Reg 4.4->4.5] Locator: Project filter does not search anymore in the middle

1. Create a "Qt Widget Applicaton" from the wizard
2. Ctrl+K, enter: "window" to find mainwindow.cpp

==> Ops, "mainwindow.cpp" is not anymore an entry. This is different to 4.4. The only entry I get here is /home/nik/opt/qt-5.9.0/5.9/gcc_64/include/QtWidgets/QMainWindow

More observations:

• "p window" ==> no mainwindow.cpp entry
• "f window" ==> OK, mainwindow.cpp is there