调整tree的引入

src/common/util.js

@@ -2,6 +2,7 @@ import dict from "./dict"
 import dayjs from './monent'
 import qs from 'query-string'
 import reg from "./regular";
+import tree from "./tree";
 
 const confirm = (content, title, config) => {
   let ops = {content}
@@ -334,5 +335,6 @@ export default {
     }
     result.forEach(removeNullChildren)
     return result
-  }
+  },
+  tree
 }