修改loading背景色（4235）

src/css/icssIndex.less

@@ -475,7 +475,7 @@
     position: absolute;
     width: 100%;
     height: 100%;
-    background-color: #000;
+    background-color: #fff;
     opacity: 0.5;
     filter:alpha(opacity=50);
     -ms-filter: "progid:DXImageTransform.Microsoft.Alpha(opacity=50);";