test: remove unused code

test/runTest/client/index.html

@@ -185,7 +185,7 @@ under the License.
                                     <div slot="header" class="clearfix">
                                         <span>Diff - {{result.diffRatio.toFixed(4)}}</span>
                                     </div>
-                                    <el-image :src="result.diff" :preview-src-list="[result.diff]"></el-image>
+                                    <el-image :src="result.diff"></el-image>
                                 </el-card>
                             </el-col>
                         </el-row>