Fix page error in default gui config

rpgregions/src/main/java/net/islandearth/rpgregions/gui/RPGRegionsGUI.java

@@ -162,7 +162,7 @@ public abstract class RPGRegionsGUI {
 
         forward.addItem(new GuiItem(forwardItem, event -> {
             event.setCancelled(true);
-            if (pane.getPages() == 0 || pane.getPage() == pane.getPages()) return;
+            if (pane.getPages() == 0 || pane.getPages() == 1) return;
 
             pane.setPage(pane.getPage() + 1);