[COOK-3241] Fix ohai_plugin recipe when not using source

The ohai_plugin recipe is requesting the `node['nginx']['source']['prefix']` attribute which doesn't exist unless you're including the source recipe (and attributes). Since `node['nginx']['binary']` is a fully qualified path including a prefix isn't necessary.
Fixed a indent
Fixed a indent
Fixed a indent

Fixed a indent
Merge branch 'master' of gh:n0ts/nginx