google says (for Raspberry pi 2&3):
sudo apt-get --only-upgrade install rbp2-mediacenter-osmc
If you have not yet downgraded to 2017.04-1 you can try downgrading just libcec with 4 commands as described here: HDMI-CEC stopped working after May update on LG and Samsung TVs - #14 by pingumale Maybe a bit less work…