build: move back to port 8601

Thanks @champierre and @takaokouji, and sorry for the trouble!

Author: cwillisf

webpack.config.js

@@ -95,7 +95,7 @@ const distConfig = baseConfig.clone()
 
 // build the examples and debugging tools in `build/`
 const buildConfig = baseConfig.clone()
-    .enableDevServer(process.env.PORT || 8602)
+    .enableDevServer(process.env.PORT || 8601)
     .merge({
         entry: {
             gui: './src/playground/index.jsx',