Relax sysctl version constraint to < 0.5.0

We use environment locking, and need sysctl v0.4.0 in our environment.

Can the sysctl version restriction be relaxed to `< 0.5.0`?

v0.5.0 contains breaking changes, see:
https://github.com/onehealth-cookbooks/sysctl/blob/master/CHANGELOG.md