this PNG image crashes application when loading

## Issue or Feature

node process is crashing with following message

```
Exception code=0xc0000005 flags=0x0 at 0x00007FFB878A7DD0. Access violation - attempting to read data at address 0x0000024B46E5D000
```

image in question:


## Steps to Reproduce

```js
var Canvas = require('canvas');
Canvas.loadImage('fail.PNG').then(canvas => console.log(canvas));
```

## Your Environment
* Version of node-canvas (output of `npm list canvas` or `yarn list canvas`): 2.6.1
* Environment (e.g. node 4.2.0 on Mac OS X 10.8): node v13.14.0 on Windows 10

## Other remarks
on linux it threw "out of memory" error on loading