Fixed my mistake from my previous pull request.

Sander,

After searching for a long time about this problem, i think that liferay use jruby-complete JAR and not jruby.
But in the portal source the JAR is named jruby.jar.

This is my mistake.

This pull request fix the issue locally for me.
And fix the original issue which is the transparent value for color in CSS file that causes errors in SASS.

Thanks for your help and one more time sorry.