fix: (netbsd)sysctl.persist (state was broken)
fix: (netbsd)sysctl.persist (state was broken)

states/sysctl calls sysctl.persist with config file, regardless of the
OS. *_sysctl do have that parameter, but netbsd_sysctl.

Now, netbsd_sysctl takes a config file with a default value like the
others.

saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt