修复前端的上传头像弹窗错误使用动态布局组件的问题：当浏览器窗口宽度小于768px，布局会发生改变，导致功能无法正常使用

ruoyi-ui/src/views/system/user/profile/userAvatar.vue

@@ -3,7 +3,7 @@
     <div class="user-info-head" @click="editCropper()"><img v-bind:src="options.img" title="点击上传头像" class="img-circle img-lg" /></div>
     <el-dialog :title="title" :visible.sync="open" width="800px" append-to-body @opened="modalOpened"  @close="closeDialog">
       <el-row>
-        <el-col :xs="24" :md="12" :style="{height: '350px'}">
+        <el-col :span="12" :style="{height: '350px'}">
           <vue-cropper
             ref="cropper"
             :img="options.img"
@@ -16,7 +16,7 @@
             v-if="visible"
           />
         </el-col>
-        <el-col :xs="24" :md="12" :style="{height: '350px'}">
+        <el-col :span="12" :style="{height: '350px'}">
           <div class="avatar-upload-preview">
             <img :src="previews.url" :style="previews.img" />
           </div>
@@ -24,7 +24,7 @@
       </el-row>
       <br />
       <el-row>
-        <el-col :lg="2" :md="2">
+        <el-col :span="2">
           <el-upload action="#" :http-request="requestUpload" :show-file-list="false" :before-upload="beforeUpload">
             <el-button size="small">
               选择
@@ -32,19 +32,19 @@
             </el-button>
           </el-upload>
         </el-col>
-        <el-col :lg="{span: 1, offset: 2}" :md="2">
+        <el-col :span="2">
           <el-button icon="el-icon-plus" size="small" @click="changeScale(1)"></el-button>
         </el-col>
-        <el-col :lg="{span: 1, offset: 1}" :md="2">
+        <el-col :span="2">
           <el-button icon="el-icon-minus" size="small" @click="changeScale(-1)"></el-button>
         </el-col>
-        <el-col :lg="{span: 1, offset: 1}" :md="2">
+        <el-col :span="2">
           <el-button icon="el-icon-refresh-left" size="small" @click="rotateLeft()"></el-button>
         </el-col>
-        <el-col :lg="{span: 1, offset: 1}" :md="2">
+        <el-col :span="2">
           <el-button icon="el-icon-refresh-right" size="small" @click="rotateRight()"></el-button>
         </el-col>
-        <el-col :lg="{span: 2, offset: 6}" :md="2">
+        <el-col :span="2">
           <el-button type="primary" size="small" @click="uploadImg()">提 交</el-button>
         </el-col>
       </el-row>