How do I remove the 'Slot 1: No SIM card detected' notification? I'm using my phone as more of a tablet computer and less of a phone (I'm not using cellular radio, only wifi Internet), so I didn't put a SIM card in it.

The issue is - the notification that I don't have a SIM card in my phone always shows up in the notification bar:



I am already running the phone in airplane mode and then enabled wifi, but the issue persists. I also tried force stopping the 'Phone' app and it does remove the notifications, but it comes back after phone restart.

How do I disable or hide these notifications permanently?

The phone is a Lenovo A536. Android version is KitKat 4.4.2.
I've recently rooted my phone and installed NotifyClean (requires the Xposed Framework). I've set it to block the Mobile Data app's 'No SIM card detected' notification:



I've previously tried to fix this issue with Notifications Off but it stops working after a device restart.