[PATCH] debuginfod/debuginfod-client.c: use long for cache time configurations

[Frank Ch. Eigler]

Hi -

> x32, riscv32, arc use 64bit time_t even while they are 32bit
> architectures, therefore directly using integer printf formats will not
> work portably.

> Use a plain long everywhere as the intervals are small enough
> that it will not be problematic.

lgtm!

- FChE