Always open popup on top-most container

src/main/java/de/johni0702/minecraft/gui/popup/AbstractGuiPopup.java

@@ -112,6 +112,9 @@ public abstract class AbstractGuiPopup<T extends AbstractGuiPopup<T>> extends Ab
     private final GuiContainer container;
 
     public AbstractGuiPopup(GuiContainer container) {
+        while (container.getContainer() != null) {
+            container = container.getContainer();
+        }
         this.container = container;
     }