Well if it's an "O" instead of a zero, that makes your info on your CoPR erroneous, and you shouldn't do your landing with such an alleged error on a document that will literally follow you your whole life, even after you eventually get Canadian citizenship.
If it's an "O", that makes your passport number on your CoPR wrong, and that's kind of a big deal.
Contact your local embassy/consulate to see how you can correct it. They will look into. Obviously you've been approved for PR so you have nothing to worry about if it's their mistake. Just don't try to ignore it and just wish for the best... Set the record straight.