perf:优化登录页面背景图

portal-manager-ui/admin/src/views/signIn/signIn.vue

@@ -214,7 +214,7 @@ export default {
   --input-height: 50px;
   --input-border-color: rgba(238, 238, 238, 1);
   --time: 1s;
-  background: url("@/assets/images/login_bg.png");
+  background: url("@/assets/images/login_bg2.jpg");
   background-size: 100% auto;
   animation: bg-roll 150s cubic-bezier(0.21, 0.07, 0.88, 1.02) infinite;
   .main {