allow 2 root nodes with v-if and v-else

[lincenying]

ver: 2.0.3
mac/chrome 53

#3887
看上面的地址说, 修复了 v-if和v-else, 可以允许两个根元素, 但是:
当v-if条件成立时, v-if能正常渲染出来
当v-if条件不成立时, v-else并不会渲染出来

Test:
https://jsfiddle.net/lincenying/h64y6bj1/4/

代码中的button, 并没有渲染出来. ( In the code v-else, does not render it. )

[yyx990803]

@chrisvfritz might want to look into this?

[lincenying]

https://cdn.jsdelivr.net/vue/2.0.3/vue.min.js
https://cdn.jsdelivr.net/vue/2.0.3/vue.js
可能是打包的问题, 用vue.min.js 有这个bug, 但是用vue.js, 并没有这个bug

( using the vue.min.js have this bug, but the use of vue.js, is not this bug )

另外, webpack的开发环境也没这个bug, 用生产环境就会出现

[chrisvfritz]

On it. Pretty sure I already know what this is and if I'm right, should be a simple fix.