/usr/share/man/man5/network.conf.5.gz is in netscript-2.4-upstart 5.2.9ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/man/man5/netscript-2.4.conf.5.gz
/usr/share/man/man5/netscript-2.4.conf.5.gz