[Nothing to fix here; this is just a note for any other reviewers to the effect that this should work for older Lantern  branches too, even though it may look otherwise (it did to me initially).] 

This works because `ln` will happily create (broken) symlinks even if the file is not found.  Otherwise this would break installs of any branch that doesn't have the pluggable transport support, because of the `set -e` at the beginning of the script.