Fix build on Arch Linux

[benwaffle]

What this PR does / why we need it: Fixes a compilation error I get when building on Arch Linux. The numeric types (e.g. uint64_t) are defined in <cstdint> and the header file needs to be included.

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):

Please check the following list:

• Does the affected code have corresponding tests, e.g. unit test, E2E test?
• Does this change require a documentation update?
• Does this introduce breaking changes that would require an announcement or bumping the major version?
• Do all new files have an appropriate license header?

[liulanzheng]

@benwaffle Thank you. Could you mind to use git commit -s --amend --no-edit to sign your name and repush it?

[benwaffle]

@liulanzheng done

[liulanzheng]

lgtm