Cannot render an Image component
| -------------------------------------------------------------------------------------------------
| Reporting a bug or issue
| -------------------------------------------------------------------------------------------------

**Expected behavior:**

Rendering an Image component should work. Going to post the reproducible test case here to make it clear:

```js
function Document() {
  return (
    <View style={{ width: 500, height: 500, backgroundColor: 'blue' }}>
      <Image
        source={{
          uri: 'http://localhost:8080/svg/image.png',
          width: 500,
          height: 500
        }}
      />
    </View>
  );
}
```

When I add the `Image` tag, it breaks. I originally thought it was because I was trying to render an SVG, but I tried it with a PNG too and still the same error.

**Observed behavior:**

This error happens:

<img width="630" alt="image" src="https://cloud.githubusercontent.com/assets/17031/26158969/527c74b2-3aeb-11e7-99c4-2d2d10ce00de.png">

The URL definitely is valid.

**How to reproduce:**

Run the above code and change the URI to a somewhere that works for you (it's localhost right now).

**Sketch version:**

43.2

