⏪ Revert "💚 rebuild node-sass for fixing Appveyor build."

This reverts commit ed90394

Author: kayo5994

appveyor.yml

@@ -16,7 +16,6 @@ install:
   - ps: Install-Product node $env:nodejs_version
   - cp qmui.config.js ../qmui.config.js
   - npm install -g gulp-cli
-  - npm rebuild node-sass
   # install modules
   - npm install