aktualizr: fix build error 'uint8_t' does not name a type

[DengkeDu]

My environment:
meta-updater: master branch [c10f9f]
yocto poky: master branch [303421]
ARCH: arm64

When I take :
bitbake aktualizr

Output error said :
uint8_t does not name a type

Add the header file cstdint to asn1-cer.h to fix it.

[pattivacek]

CI is failing due to the formatter. It's quite minor, just capitalization:

+#include <cstdint>
 #include <stdexcept>
 #include <string>
-#include <cstdint>

The shellchecker also failed, but not because of your change, so we can ignore that for the moment.

[pattivacek]

I've made a PR with the shellcheck fix here: #101. No need to worry about that here, but please do fix the formatting complaint relevant to this PR.

[DengkeDu]

Ok, thanks, i will send V2.