Unable to find/create a proof .doc document, so only implementing this
for .docx

Change-Id: I3a0cb2ddf7b3aeecc9200e595f70d8c88af4b122
Reviewed-on: https://gerrit.libreoffice.org/28501Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Michael Stahl <mstahl@redhat.com>