minor: optimize style

Author: Renjie Jin

web/src/views/Initialize.vue

@@ -433,10 +433,9 @@
 
   #install {
     font-family: "Helvetica Neue", Helvetica, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "微软雅黑", Arial, sans-serif;
-    height: 100%;
+    display: flex;
     text-align: center;
     background-color: #f0f2f5;
-    display: flex;
     justify-content: center;
     align-items: Center;