__netbox: fix shellcheck by changing parameter checks

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.

type/__netbox/files/ldap_config.py.sh

@@ -1,7 +1,7 @@
 #!/bin/sh
 
 # no configuration if there are no ldap parameters
-if ls -1qA "$__object/parameter"/ldap-* | grep -q .; then
+if [ "$(find "$__object/parameter/" -type f -name 'ldap-*' -print)" ]; then
     # skip
     cat << EOF
 ##############################