"BadRequestError: Must provide query string."
I've been  trying to post image using curl . we are using `koa-graphql`.
Below is my mutation along with resolvers, but I keep getting error message:

```
error mesage { BadRequestError: Must provide query string.
    at result (/home/**/facade-srv/node_modules/koa-graphql/dist/index.js:121:42)
    at new Promise (<anonymous>)
    at middleware (/home/***/facade-srv/node_modules/koa-graphql/dist/index.js:114:22) message: 'Must provide query string.' }
```

 Mutation:
```js
import { mutationWithClientMutationId } from 'graphql-relay';
import { myContext } from '../../../iam/interfaces';
import { EndpointHandler } from './../../../EndpointHandler';
import { GraphQLUpload } from 'graphql-upload'

export default mutationWithClientMutationId({
    name: 'createFileuploads',
    inputFields: {
        file: {
        type: GraphQLUpload
        

    }},
    mutateAndGetPayload: async ({ file }, ctx: MyContext) => {
      console.log(file);
      const { filename, mimetype, createReadStream } = await file
      const stream = createReadStream();
      console.log('stream data is :',stream);
      // return tryRequest('create', parseResourceList(uploadImage, 'create', 'device_type', ctx), ctx);
    },
    outputFields: EndpointHandler.buildCreateMutationOutput(""),
  });
```
Curl request:

```
curl http://localhost:5000/graphql \
-F operations='{ "query":"mutation ($file: Upload){ createFileUploads(file: $file) }","variables": { "file": null} }' \
-F map='{ "0": ["variables.file"] }' \
-F 0=@/desktop/test.txt
```

Please suggest if I am doing something wrong in my curl reqeust ?


