Fix switchTab usage of tabOrder

tabview.lua

@@ -49,7 +49,12 @@ local function switchTab()
     local idx = 0
     if currentTab ~= nil then
         currentTab.window.setVisible(false)
-        idx = tabOrder[currentTab.name]
+        for i, name in pairs(tabOrder) do
+            if name == currentTab.name then
+                idx = i
+                break
+            end
+        end
     end
     idx = idx + 1
     if idx > tabCount then