overhauled registry

src/main/java/de/srsoftware/web4rail/actions/ShowText.java

@@ -21,6 +21,11 @@ public class ShowText extends TextAction{
 		return new Label(t("Text to display on clients:")+NBSP);
 	}
 	
+	@Override
+	protected void removeChild(BaseClass child) {
+		// this class has no child elements		
+	}
+	
 	@Override
 	public String toString() {
 		return t("Display \"{}\" on clients.",text);