Doesn't work with mixed http/https served sites

First off, awesome plugin. Does precisely what I needed. But my client recently wanted to serve the pages with forms over ssl. I've got the patrol plugin managing the redirects, but Compressor was hardcoding the asset url's to whatever the siteUrl was. So the https pages weren't getting any assets. 

I've updated the CompressorService to check for https and then pass the protocol on the the getSiteUrl method to generate the right url. This fixed the issue for me.