Ionic2 Wired things that I can't remove the tab from the page

Hi ,

I’m writing a toy app with ionic 2, the problem is that I add a tab in footer bar but even if I remove it from the code, when I run the app with ionic serve I still see it is there.

Could you please take a look at below code and show me clue here, I thank you very much .

best regards,

anybody can help on this ?
thank you very much