git2::IndexTime is not ready for year 2038

[samvv]

Trying to construct a git2::IndexTime, I noticed that the signature of new is not year 2038 compatible.

pub fn new(seconds: i32, nanoseconds: u32) -> IndexTime

The function takes a signed 32-bit integer, which will overlow somewhere in 2038.

More information at https://theyear2038problem.com/

I see that the issue seems to be fixed in master but not yet published. I'll close this issue if the new version gets published.