Default Installing the OTA update on terminal Root / CWM

Hi,New to this forum I am the happy owner of an moto g.
I received a message telling me update saying that the update 4.4.4 update was available.So I download and I install.However, during the update, it does not work. To install the phone reboots, then CWM proposes to install the package but the installation fails for failure of signature verification.
What is the manipulation to do about it?(Need install rom Stock ?)

PS:Yesterday I Unroot my moto g with SuperSu but it has the same problem (except that my moto g is unroot (verified by Root checker))