Zimcheck does not complains on externals background-image: url("...")

[benoit74]

When a page has an element with an inline style with a background-image referring to an external URL, zimcheck should raise an error.

Exemple:

<div style="background-image:url(&quot;https://i.ytimg.com/vi/ppSnb4A2WWw/hqdefault.jpg&quot;)" width="560" height="315"></div>

[rgaudin]

Yes, zimcheck relies on regexp and has many limitations. We already have several tickets but I believe the potential solution is laid out in #149

[kelson42]

@rgaudin Definitly! One small problem, it seems that libgumbo is not maintained anymore :(

[kelson42]

Blocked by #331