CURLcode
Before this patch, the result code was a mixture of `int` and `CURLcode`. Also adjust casts and fix a couple of minor issues found along the way. Cherry-picked from #13489 Closes #13600
When the user was providing the header X-XXX-Date, the header was re-added during signature computation, and we had it twice in the request. Reported-by: apparentorder@users.noreply.github.com Signed-off-by: Matthias Gatto <matthias.gatto@outscale.com> Fixes: https://github.com/curl/curl/issues/11738 Closes: https://github.com/curl/curl/pull/11754