Don't break with newer flask-multipass
Don't break with newer flask-multipass

This makes it easier for developers to use the 2.3 configs on 2.2, even
though it still requires manually editing the version pinning.

DirkHoffmann/indico,mic4ael/indico,mic4ael/indico,mic4ael/indico,mic4ael/indico,DirkHoffmann/indico,indico/indico,DirkHoffmann/indico,pferreir/indico,indico/indico,pferreir/indico,pferreir/indico,DirkHoffmann/indico,indico/indico,pferreir/indico,indico/indico,ThiefMaster/indico,ThiefMaster/indico,ThiefMaster/indico,ThiefMaster/indico