Changes for Rollup (#12924)

* Changes for rollup

* remove variables.less
diff --git a/erpnext/public/build.json b/erpnext/public/build.json
index 21cd289..0ce5c75 100644
--- a/erpnext/public/build.json
+++ b/erpnext/public/build.json
@@ -1,6 +1,6 @@
 {
     "css/erpnext.css": [
-        "public/css/erpnext.css"
+        "public/less/erpnext.less"
     ],
     "js/erpnext-web.min.js": [
         "public/js/website_utils.js",