fftw: fix editing of cmake config files
fftw: fix editing of cmake config files

JPeterMugaas/MINGW-packages,oscarfv/MINGW-packages,JPeterMugaas/MINGW-packages,lhmouse/MINGW-packages,oscarfv/MINGW-packages,stahta01/MINGW-packages,lhmouse/MINGW-packages,lhmouse/MINGW-packages,stahta01/MINGW-packages,stahta01/MINGW-packages,JPeterMugaas/MINGW-packages,JPeterMugaas/MINGW-packages,stahta01/MINGW-packages,oscarfv/MINGW-packages,JPeterMugaas/MINGW-packages,oscarfv/MINGW-packages,JPeterMugaas/MINGW-packages,stahta01/MINGW-packages,stahta01/MINGW-packages,oscarfv/MINGW-packages,oscarfv/MINGW-packages,lhmouse/MINGW-packages,lhmouse/MINGW-packages,lhmouse/MINGW-packages