can not install executable-hooks gem

[mkristian]

trafficstars

this gem executes code when installing the extension and this code fails with jruby-complete.jar

the problem is that files inside the jruby-complete.jar are not writable and there are a few bin-stubs bundled with this jar.

[mkristian]

https://github.com/rvm/executable-hooks/pull/22 would fix the issue since the check will now leave those bin-stubs from the jar alone.