fix: base header

Author: ReneSchwarzer

src/WebExpress.WebApp/WebPage/VisualTreeWebApp.cs

@@ -110,6 +110,7 @@ public override IHtmlNode Render(IVisualTreeContext context)
             var renderContext = new RenderControlContext(context.RenderContext);
             html.Head.Title = I18N.Translate(context.Request, Title);
             html.Head.Favicons = Favicons;
+            html.Head.Base = Base?.ToString();
             html.Head.Styles = Styles;
             html.Head.Meta = Meta;
             html.Head.Scripts = HeaderScripts;