This caused a lot of hubbub in the past. Microsoft has cut off numerous WP8 phones from receiving more Insider updates a few months ago. However, if you switch to production you'll probably receive some more bug fixes.
It basically means turning off Insider, AKA the "Production" ring. So whatever option you have in the Insider app to turn off/unenroll from the Insider program.
I have left the programme in the end it said a production update is available for my phone. I went to settings and then to phone & update but still there is no notification of an update?