shadow: disable nscd feature when glibc is not built with spawn posix functions
shadow package configure step fails with this log output :
| checking location of faillog/lastlog/wtmp... (cached) /var/log
| checking location of the passwd program... (cached) /usr/bin
| checking for posix_spawn... no
| configure: error: posix_spawn is needed for nscd support
| Configure failed. The contents of all config.log files follows to aid debugging
| ERROR: oe_runconf failed
Signed-off-by: Baptiste DURAND <baptiste.durand@gmail.com> Signed-off-by: Ross Burton <ross.burton@intel.com>
