Vue self-closing tags cause double-printing

Was running vue on gitlabhq and ran into this:

**Input:**

```vue
<script>
</script>

<template>
  <br />
</template>
```

**Output:**

```vue
<script>
</script>

<template>
  <br />
</template><script>
</script>

<template>
  <br />
</template>
```
  
/cc @vjeux 