@Rich-C Tom has also been telling us the newer trunk kernels will work with 1.2.0 stable. So if you backup your current kernels you can download the latest trunk version using the following commands on your fog server. Just navigate to /var/www/html/fog/service/ipxe , rename the files and then execute these commands.
sudo wget https://fogproject.org/kernels/bzImage
sudo wget https://fogproject.org/kernels/bzImage32
These kernels are 4.5.3 as of today.
I do have to say my personal recommendation is to just upgrade to the trunk release to take advantage if the new features (as long as you can tolerate a little instability of the dev releases).