Double encoding of query

seems that query is encoded one more time when hitting express.
I had to add this peace of code before passing event to module:
```js
exports.handler = (event, context) => {
Object.keys(event.queryStringParameters).forEach((key) => {
// eslint-disable-next-line no-param-reassign
event.queryStringParameters[key] = decodeURIComponent(event.queryStringParameters[key]);
});
awsServerlessExpress.proxy(server, event, context);
};
```