chore: modify __PLACEHOLDER__ default value

vue.config.js

@@ -10,7 +10,7 @@ const isRelease = false
 
 const features = {
   __DEV__: !isProd,
-  __PLACEHOLDER__: isProd || !isRelease
+  __PLACEHOLDER__: !isProd || !isRelease
 }
 
 const copyFiles = [