Don't sort subsetter options when values are specified rather than derived.

[samussiah]

relevant line of code: https://github.com/RhoInc/Webcharts/blob/master/src/controls/makeSubsetterControl.js#L15

Test notes

• Confirm in CAT that all of the filters in each of the individual renderers work as expected. In CAT click More Options and use "subsetter" for the Webcharts version.