Fix for ChoiceView.findIndexOfChoice() when passed null.
Fix for ChoiceView.findIndexOfChoice() when passed null.

TanayParikh/foam2,jacksonic/vjlofvhjfgm,foam-framework/foam2,foam-framework/foam2,foam-framework/foam2,jacksonic/vjlofvhjfgm,TanayParikh/foam2,TanayParikh/foam2,TanayParikh/foam2,jacksonic/vjlofvhjfgm,foam-framework/foam2,foam-framework/foam2