message: rand: only try and use freeifaddrs if available
diff: #include <sys/utsname.h>
  #include <unistd.h>
  #endif
  -#if HAVE_DECL_GETIFADDRS
  +#if HAVE_DECL_GETIFADDRS && HAVE_DECL_FREEIFADDRS
  #include <ifaddrs.h>
  #endif
  #if HAVE_SYSCTL
  @@ -361,7 +361,7 @@ void RandAddStaticEnv(CSHA512& hasher)
  hasher.Write((const unsigned char*)hname, strnlen(hname, 256));
  }
  -#if HAVE_DECL_GETIFADDRS
  +#if HAVE_DECL_GETIFADDRS && HAVE_DECL_FREEIFADDRS
  // Network interfaces
  struct ifaddrs *ifad = NULL;
  getifaddrs(&ifad);
  