message: assume webpackStatsSupported true when no version is set
diff: @@ -23,7 +23,9 @@ export const setSourceDir = async (ctx) => {
  };
  export const setSpawnParams = async (ctx) => {
  - const webpackStatsSupported = semver.gte(semver.coerce(ctx.storybook.version), '6.2.0');
  + const webpackStatsSupported = ctx.storybook.version
  + ? semver.gte(semver.coerce(ctx.storybook.version), '6.2.0')
  + : true;
  if (ctx.git.changedFiles && !webpackStatsSupported) {
  ctx.log.warn('Storybook version 6.2.0 or later is required to use the --only-changed flag');
  }
  