For DOCX, there is a single setting to indicate the use of even
headers/footers. So, if either one of these has a separate
even, then create an even for both.

In 2017, nBreakCode was used to write an empty footer to
prevent inheriting any previously defined footer.
So I also removed the obsolete debug.

Change-Id: I3ec4a399103679092e6a6ec3a7ae9b1ae303cc3e
Reviewed-on: https://gerrit.libreoffice.org/65699
Tested-by: Jenkins
Reviewed-by: Justin Luth <justin_luth@sil.org>