Closing parenthesis of conditional spread removed erroneously

I've got a transform to remove empty object spreads like `...{}`:

```
module.exports = {
default: function(file, api, options) {
const j = api.jscodeshift;
const ast = j(file.source);

ast
.find(j.SpreadProperty, {argument: {type: 'ObjectExpression'}})
.filter(p => p.node.argument.properties.length === 0)
.remove();

return ast.toSource();
},
parser: 'flow',
};
```

I'm running it against the following code:

```
let cond = false;
let obj = {
...(cond ? {x: 4} : {y: 5}),
...{},
};
```

The result of the transform is as follows:

```
let cond = false;
let obj = {
...(cond ? {x: 4} : {y: 5}
};
```

You can see that the closing parenthesis of the conditional spread was removed, resulting in broken syntax. I get the same result if I move the empty object spread above the conditional spread.

I attempted to reproduce the issue in `recast` (0.15.0) directly:

```
const recast = require('recast');
const flow = require('recast/parsers/flow');
const builders = recast.types.builders;

recast.run(
function(ast, callback) {
recast.visit(ast, {
visitSpreadElement: function(path) {
const arg = path.node.argument;
if (arg.type === 'ObjectExpression' && arg.properties.length === 0) {
path.prune();
return false;
}
this.traverse(path);
},
});

callback(ast);
},
{
parser: flow
}
);
```

But its output is correct:

```
let cond = false;
let obj = {
...(cond ? {x: 4} : {y: 5})
};
```