/usr/share/proftpd/templates/vroot.conf is in proftpd-mod-vroot 0.9.2-2build5.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/proftpd/templates/../../doc/proftpd-mod-vroot/vroot.conf
/usr/share/proftpd/templates/../../doc/proftpd-mod-vroot/vroot.conf