Then make a resolution specifically banning states from using trivial offense to limit a demographic's democratic influence; I agree with your point, but I still think there are plenty of scenarios where
a. Previous criminal record can be a legitimate reason to prevent someone from voting; even if its temporary or specified to different types of elections
and
b. Disenfranchisement can be a legitimate punishment
And while the resolution may be a solution to your potential problem, it does not account for criminal justice systems which hold the above beliefs, and thus is not good international legislation imo.