image.png%22 404 (Not Found) in Chrome

Hi there,

First of all, a very big thank you for this plugin!
The plugin is working very nice but my console is throwing weird messages:

```
> GET http://localhost:9000/%22http://localhost:9000/images/campaign/aw1617/preloader-image.png%22 404 (Not Found) --- preloader-image.png%22:1
> GET http://localhost:9000/%22http://localhost:9000/bower_components/photoswipe/dist/default-skin/default-skin.png%22 404 (Not Found) --- default-skin.png%22:1
```

Surprisingly those images come from CSS as background images.

I have checked that deactivating the plugin those error do not appear.
It only appears in Chrome. I have tested in latest versions of Safari and Firefox.

Chrome Version 52.0.2743.116 (64-bit) Mac OS X
The project is a Yeoman webapp (using browser-sync, gulp, bower, sass, etc)

Thanks

Reproduce the issue in Chrome 52 using the Yeoman webapp setup described, then inspect the plugin's handling of CSS background images for preloader-image.png and default-skin.png. Done means the plugin no longer requests URLs containing encoded quotes and the reported 404 messages disappear.

Written by the indexing model from the issue text.