Previously krfb had version set to 5.0. This is misleading.
Now, do the same as other standard KDE apps, like ark or dolphin: use
KDE_APPLICATIONS_VERSION_MAJOR, KDE_APPLICATIONS_VERSION_MINOR, etc.
This page: https://www.kde.org/applications/system/krfb has a link to report a bug: https://bugs.kde.org/enter_bug.cgi?format=guided&product=krfb
Versions in bugzilla have 17.xx.xx, so "About..." window should match.
cmake: Set version in project(); use ecm_setup_version() call
Inspired by commit: https://cgit.kde.org/ark.git/commit/?id=cffecfbfffd22bc0bbe451ed8d74f3b6da113c6f
cffecfbfffd22bc0bbe451ed8d74f3b6da113c6f