If a unit has a statement such as User=0day where the username exists but is
strictly speaking invalid, the unit will be started as the root user instead.
Backport a patch from upstream to mitigate this by refusing to start units such
as this.
(From OE-Core rev: 549cb941c5b19909fb00f2bef9c04172ca1c162d)
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>