See c127c19d "Remove HAVE_CXX11_REF_QUALIFIER,
always true now".  By now, any outdated builders where this would fail should
have been identified and taken care of.

Change-Id: I5f823b48b40dd6a20991ebb118e077a0e88aacb1
Reviewed-on: https://gerrit.libreoffice.org/38887Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>