perf[login.vue]: add tabindex for login form (PanJiaChen#1933)

Author: marxangels

src/views/login/index.vue

@@ -19,6 +19,7 @@
           :placeholder="$t('login.username')"
           name="username"
           type="text"
+          tabindex="1"
           auto-complete="on"
         />
       </el-form-item>
@@ -35,6 +36,7 @@
             :type="passwordType"
             :placeholder="$t('login.password')"
             name="password"
+            tabindex="2"
             auto-complete="on"
             @keyup.native="checkCapslock"
             @blur="capsTooltip = false"