Fix for JDK-8201483 broken '-' containing features

[Chris Dennis]

Hi All,

It looks like the addition of support for disabling features has broken support for enabling features that contain a ‘-‘ in their name (amusingly this includes the 'all-gcs’ feature).

Pretty sure this is the offending code is the use of 'match($i, /-.*/)’ to distinguish between disabled and enabled features. That regex needs to match a ‘-' only at the beginning of the line otherwise configures thinks you are disabling the ‘ll-gcs’ feature.

Thanks,

Chris Dennis