change string ReuseFactor to int

Created by: jmitrevs

This is a minor fix for when a configuration doesn't have a ReuseFactor set. Most of the code, and hls4ml-tutorial suggests that the ReuseFactor should be an int and not a string . I think we should agree that it should always be an int and not a allow a string.

I ran into this problem testing onnx models with quartus in a different branch, but the issue is not specific to that branch or input.