DEVELOPERS: add Christian Stewart to balena-engine package
Signed-off-by: Christian Stewart <christian@paral.in>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
(cherry picked from commit fc644ed3be1ae52bf883f93083fc96f9fe1f2ee4)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>