Default `nologin` shell is not valid on all systems
Related to #1553 (closed)
Omnibus uses /bin/nologin
for users such as gitlab-redis
. This may be valid on some systems (I'm not sure) but other systems use /sbin/nologin/
or /usr/sbin/nologin
. We should ensure we're using a valid nologin
location, or use something like /bin/false
as a fallback.