slapos_panel: Redirect to contact us if payment_mode isn't supported

   Since payzen/wechat depends on specific currency, so keep default implementation generic, so it allows the user get a contact us message, so it permits the system use wire transfer or non-automatic payments, to proceed with payment.

master/bt5/slapos_panel/SkinTemplateItem/portal_skins/slapos_panel/PaymentTransaction_redirectToManualPayment.py

@@ -3,4 +3,4 @@ if (context.getPaymentMode() == "wechat"):
 elif (context.getPaymentMode() == "payzen"):
   return context.PaymentTransaction_redirectToManualPayzenPayment()
 else:
-  raise NotImplementedError('not implemented')
+  raise context.PaymentTransaction_triggerPaymentCheckAlarmAndRedirectToPanel(result="contact_us")