The latest versions don't have that condition anymore, since we've long since dropped support for Unity 4.x
For the 5.x cycle, we use #if UNITY_5_X_OR_NEWER
which seem to be correctly defined in 2017.x
Looks like an old version of the script made its way into the unitypackage for some reason. I'll see to updating it.
No wait. I opened the wrong project. The latest works fine.