LibWeb: Allow having a linear-gradient() as a background-image

Author: https://github.com/MacDue
Commit: ee7e9e7c86
Pull-request: https://github.com/SerenityOS/serenity/pull/14564
Reviewed-by: https://github.com/AtkinsSJ

Userland/Libraries/LibWeb/HTML/HTMLHtmlElement.cpp

@@ -21,7 +21,7 @@ bool HTMLHtmlElement::should_use_body_background_properties() const
     auto const& background_layers = layout_node()->background_layers();
 
     for (auto& layer : background_layers) {
-        if (layer.image)
+        if (layer.background_image)
             return false;
     }