For backward compatibility, the Linux capabilities macros exposes v1 semantics
(32-bit) by default. We probe the version at runtime (because of pre-compiled
binaries) but the kernel syscall API is conservative and it doesn't return a
64-bit capability version if the input version is v1.
This patch suppress the kernel > 5.0 dmesg log below:
capability: warning: 'unitd' uses 32-bit capabilities (legacy support in use)
