MessageBox: fix icon position error (#17410)

packages/message-box/src/main.vue

@@ -28,6 +28,7 @@
           </button>
         </div>
         <div class="el-message-box__content">
+          <div class="el-message-box__container">
             <div
               :class="['el-message-box__status', icon]"
               v-if="icon && !center && message !== ''">
@@ -38,6 +39,7 @@
                 <p v-else v-html="message"></p>
               </slot>
             </div>
+          </div>
           <div class="el-message-box__input" v-show="showInput">
             <el-input
               v-model="inputValue"

packages/theme-chalk/src/message-box.scss

@@ -73,12 +73,15 @@
   }
 
   @include e(content) {
-    position: relative;
     padding: 10px $--msgbox-padding-primary;
     color: $--messagebox-content-color;
     font-size: $--messagebox-content-font-size;
   }
   
+  @include e(container) {
+    position: relative;
+  }
+
   @include e(input) {
     padding-top: 15px;