A few days ago I installed Windows Insider (on my Lumia 521) and chose the Fast Track. So now I have a phone update that's ready to download. (I've unchecked "Automatically download updates if my data settings allow it".)
But I don't want to download and install the update. I used Windows Insider intending to get Windows Phone 8.1 Update 2 (following the instructions here), but it looks like the update will be Windows 10. I don't want to install Windows 10, because it's supposed to be slow as molasses. I've since uninstalled Windows Insider.
I'm periodically getting notifications that an update is available. How do I disable these notifications (or the update that's ready to download)? I don't see an option for disabling the update notifications in notifications+actions.