Fix issues on weight adjust module (#201)

1.The updateId keeps available after executing a put request. You will update a record on create dialog after doing an update operation.
2.The create dialog will not automatically close after getting server response. Because the http status code is 201.
3.The post request get wrong weight parameter
diff --git a/dubbo-admin-frontend/src/components/governance/WeightAdjust.vue b/dubbo-admin-frontend/src/components/governance/WeightAdjust.vue
index 433ba02..f21b34e 100644
--- a/dubbo-admin-frontend/src/components/governance/WeightAdjust.vue
+++ b/dubbo-admin-frontend/src/components/governance/WeightAdjust.vue
@@ -260,6 +260,7 @@
         this.readonly = false
       },
       openDialog: function () {
+        this.updateId = ''
         this.dialog = true
       },
       openWarn: function (title, text) {