ujail: search libs in /lib before /lib64
musl (openwrt DD r47603 x86-64) looks for lib only in /lib,
not in /lib64, and /lib64 is a symlink to /lib, so ujail find
all the libs in /lib64, add them in the jail (only under /lib64)
and then musl fails to find the libs.
uClibc (openwrt CC r47608 x86-64) looks for lib in /lib and
/usr/lib, not in /lib64 (/lib64 is also a symlink to /lib)
/lib64 is before /lib since the first commit, i don't know
if it was on purpose
this partly fixes
https://dev.openwrt.org/ticket/20785
Signed-off-by: Etienne CHAMPETIER <champetier.etienne@gmail.com>