Use less greedy inverse set match.

Rather than using a greedy wildcard like so:

* `%r{^\d+:.+:/(lxc|docker)/.+$}`

Use a less greedy inverse set, which excludes literal colon:

* `%r{^\d+:[^:]+:/(lxc|docker)/.+$}`

Discussion, https://github.com/atomic-penguin/ohai/commit/02d1a30a9369b8266082ff2e29fb22ec38ecb999#diff-725858488c1235840f3a62b4eb7a575fR149