Using protocal agnostic urls (//domain.com/css.css) in @import causes CSS aggregation to drop those files

Problem: attempt to use @import in stylesheets with a protocol agnostic url so that they server over either http or https:

@import url(//fonts.googleapis.com/css?family=Open+Sans:400,700,300,600,800);

Then turn on CSS aggregation. This line is dropped from the aggregated CSS file. It appears to be that the regex is improperly seeing this as a local file to include, and then can't find it. Once it can't find it it drops it from the aggregated CSS file. There are alternate ways to do this, but this should work with @import.