The prohibition against honey is that it might have small amounts of botulism in it. This is something that older people can ward off really well, but infants can't, so no honey for babies in their first year.
Corn syrup does not have this problem (it is processed). So its safe.
There are other reasons to try and find applesauce that is not sweetened with corn syrup (like trying to allow the apple taste to speak for itself). However, a jar of applesauce is not going to harm your baby - so don't panic. It is only something you may want to consider when viewing your baby's diet over all. (Some corn syrup - ok, corn syrup in every item - not so much.)