Remove arc4random() OpenBSD support The arc4random() support for OpenBSD does not build. The intention was to include any portability code so that the library could be easily ported to such systems, but it makes little sense to build it on OpenBSD where most of the functionality will be already present, or the software would have been ported anyway. [guillem@hadrons.org: Reword commit message to add rationale. ] Closes: !15 Signed-off-by: Guillem Jover <guillem@hadrons.org>