[REG Qt 5.5.0 -> Qt 5.5.1] CMake: Pointless subdir "." in Projects view

1. Run Creator on Qt built from current 5.5 branch.
   I used 1497a398e34e18abb18f705b2294464840629ca1 .
2. Open src/CMakeLists.txt from SpeedCrunch and follow the wizard.
3. See the contents of Projects view.
   It contains a subdirectory named "." which contains the files cmake_uninstall.cmake.in, CMakeLists.txt, SourceFiles.cmake and main.cpp.

This subdirectory is pointless. These files should be displayed in the root level instead. With Qt 5.5.0, this works correctly.

If this turn out to be a bug in Qt, please forward the report.

Found by Squish test tst_cmake_speedcrunch.