Silence warnings that we don't care about
We get a lot of warnings of the form
xAOD::TEvent::getEvent... WARNING Can't find EventFormatElement for hashed SG key 232541402
which seem harmless. I asked about this on mattermost but I'm also putting a reminder here. Since this might be an ATLAS-wide problem I could just make a MR to TEvent which gives an option to turn these warnings off, but if someone has a better idea it's welcome.
Nagging @khoo as someone who knows more about this stuff than I do.