remove unused vars and ga event on version selector

Author: recrwplay

src/js/01-nav.js

@@ -57,8 +57,8 @@
     versionSelector.addEventListener('change', function (e) {
       const target = e.target
 
-      const current = target.dataset.current
-      const next = target.selectedOptions[0].dataset.version
+      // const current = target.dataset.current
+      // const next = target.selectedOptions[0].dataset.version
 
       const url = target.value