fix: missing template throw exeption

application/source/document/html.go

@@ -170,6 +170,9 @@ func extractTemplate(env *BuildHtmlEnvironment, doc *html.Node, id string) {
 	checkError(err)
 
 	node := cascadia.Query(doc, sel)
+	if node == nil {
+		return
+	}
 	node.Parent.RemoveChild(node)
 
 	container := html.Node{