1. ruby/host build fails on macos due to Apple ld generates warning
if a folder from LDFLAGS is not exist. configure script catches this
warning and fails. This patch disables ld warnings for macos
2. ruby build fails on macos due /bin/true is not exist on macos.
This patch replaces /bin/true with true in OpenWrt Makefile
Signed-off-by: Sergey V. Lobanov <sergey@lobanov.in>