This should not happen, but we've seen some cases where it would cause a crash, usually
when a previous upgrade did something a bit weird (in this specific case; a printer
with an empty variant, whereas it should have a variant).
Since any change that the user will make will ensure that the variant is no longer empty (eg;
any selection of a variant will mean it's no longer empty) and that there is no way back,
it should be pretty safe to ignore the situation as it will resolve itself eventually
CURA-6992
fb4ce43f0c