Editors and filesystems may create artifacts related to .conf files
which don't change the file suffix; these artifacts generally begin
with "." so that they don't appear in normal directory listings
(e.g. ".#filename" for emacs interlock files). Make sure to ignore
any such artifacts when processing a profile includedir directive.
(cherry picked from commit e8e1d841f8e43e4f441b451d91333a01e43c1b6f)