Problem with scrub_css when value is rgb

[SavenkoSy]

After updated from 2.0.3 -> '2.1.1'

When the version is 2.0.3:
Loofah::HTML5::Scrub.scrub_css "color: rgb(255, 0, 0)"
=> "color: rgb(255, 0, 0);"

When the version is 2.1.1:
Loofah::HTML5::Scrub.scrub_css "color: rgb(255, 0, 0)"
=> ""

[tschoppi]

Might be solved with manual intervention after #123 has been merged.

[flavorjones]

Will be fixed in the next release, likely named v2.2.0.