Remove timestamp from server hello
Remove timestamp from server hello

This change mirrors https://github.com/awslabs/s2n/pull/487 by removing the
timestamp from the server hello.

This isn't much of a security measure, in most cases the application protocol
(e.g. HTTP) leaks the time anyway, but this does make us more compatible with
OpenSSL's behavior and it removes a call to time() from our codebase.

colmmacc/s2n,colmmacc/s2n,alexeblee/s2n,wcs1only/s2n,wcs1only/s2n,awslabs/s2n,bpdavidson/s2n,gibson-compsci/s2n,alexeblee/s2n,alexeblee/s2n,raycoll/s2n,PKRoma/s2n,colmmacc/s2n,wcs1only/s2n,bpdavidson/s2n,PKRoma/s2n,PKRoma/s2n,wcs1only/s2n,awslabs/s2n,alexeblee/s2n,alexeblee/s2n,jldodds/s2n,raycoll/s2n,wcs1only/s2n,raycoll/s2n,colmmacc/s2n,PKRoma/s2n,bpdavidson/s2n,wcs1only/s2n,raycoll/s2n,awslabs/s2n,PKRoma/s2n,raycoll/s2n,gibson-compsci/s2n,colmmacc/s2n,bpdavidson/s2n,gibson-compsci/s2n,jldodds/s2n,alexeblee/s2n,PKRoma/s2n,gibson-compsci/s2n,wcs1only/s2n,PKRoma/s2n,jldodds/s2n,raycoll/s2n,colmmacc/s2n,wcs1only/s2n,jldodds/s2n,gibson-compsci/s2n,PKRoma/s2n,awslabs/s2n,jldodds/s2n,gibson-compsci/s2n,awslabs/s2n,awslabs/s2n,bpdavidson/s2n,bpdavidson/s2n