feat(@rbc/rbc-login): 用纯白加载画面显得加载很快(

develop/@rbc/rbc-login/src/views/login/index.vue

 <template>
   <div class="login-wrapper">
+    <div v-if="imgLoading" class="white-loading"></div>
     <img v-if="loginImageBg" :src="loginImageBg" class="login-img-bg" />
     <div class="bg-color-class" />
     
@@ -154,14 +155,6 @@ export default {
     },
   },
   watch: {
-    imgLoading(val) {
-      if (val) {
-        this.$Spin.show()
-      }
-      else {
-        this.$Spin.hide()
-      }
-    }
   },
   methods: {
     getImgUrl(imgCode) {
@@ -301,6 +294,13 @@ export default {
   background-size: cover;
   overflow: hidden;
   position: absolute;
+  .white-loading {
+    position: absolute;
+    width: 100%;
+    height: 100%;
+    background-color: white;
+    z-index: 2000;
+  }
   
   .login-img-bg {
     width: 100%;