Switch: fix switch blinking in ssr (#10484)

* fixed #3800

https://github.com/ElemeFE/element/issues/3800 fixed

* Switch:fix switch will blink when render in server beause its default width is 0.

packages/switch/src/component.vue

@@ -58,7 +58,7 @@
       },
       width: {
         type: Number,
-        default: 0
+        default: 40
       },
       activeIconClass: {
         type: String,