fix Button to bug

examples/routers/button.vue

@@ -311,6 +311,7 @@
         <Divider></Divider>
         <Button to="http://baidu.com" replace>http跳转</Button>
         <Button to="https://iviewui.com" replace>https跳转</Button>
+        <Button :to="{path: '/icon'}">Router 对象跳转</Button>
     </div>
 </template>
 <script>

src/mixins/link.js

@@ -55,7 +55,7 @@ export default {
                 window.open(to);
             } else {
                 if (router) {
-                    if (this.to.includes('//')) {
+                    if ((typeof this.to === 'string') && this.to.includes('//')) {
                         window.location.href = this.to;
                     } else {
                         this.replace ? this.$router.replace(this.to, () => {}) : this.$router.push(this.to, () => {});