Revert "initial perf, which gets stripped out in production (#4131)" (#4636)

This reverts commit 5ea2150ae7.

webpack-watch.config.js

@@ -5,9 +5,4 @@ config.plugins = config.plugins.filter(plugin => {
   return plugin.constructor.name !== "UglifyJsPlugin"
 })
 
-config.module.rules = config.module.rules.filter(rule => {
-  // Disable minification
-  return rule.loader != "webpack-strip-block"
-})
-
 module.exports = config