It seems like that Apple has simply stopped signing iOS 8.1.2 and this can be a dangerous information for jailbreakers. This signifies that iOS 8.1.2 can no longer be put in on a tool, and as such, you'll be able to no longer jailbreak in case you repair your software. Jailbreakers will want to keep the place they're on iOS 8.1.2 in the event that they need to stay their jailbreaks.
So for now you'll have to watch out and take a look at to not set up any cracked jailbreak tweaks/topics or and so forth.. which might hurt your software and pressure you to revive or update your iPhone's tool as you are going to lose your jailbreak..
You are warned !