The working `ls | grep .` like solution was dropped based on the
shellcheck warning. Rather a solution with `find(1)` is used.
As alternative, it could be simply checked if the glob succeeds or not
by test all given arguments if there are existing files. It was dropped
in question if it's really better than the `find(1)` solution.
The ldap config file will be empty (only comments) if no parameter
name set matches `^ldap-*`.
It still generate a ldap config if one or more ldap parameters are set,
but not all basic parameters.