I get a warning under MacOSX of

argument unused during compilation -I . -Werror,-Wunused-command-line-argument

Change-Id: I0ae48783eefa52a829471e51a94c79d235dc2f38
Reviewed-on: https://gerrit.libreoffice.org/39988Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>