bnc#865381 DOCX import: handle w:jc=center inside w:textDirection=btLr

Change-Id: I102c70429457515b34e74cb8e82e1417e6276d1d
(cherry picked from commit 3325e0f206ce864730468c3556ce06760042c157)
Reviewed-on: https://gerrit.libreoffice.org/10049
Reviewed-by: Andras Timar <andras.timar@collabora.com>
Tested-by: Andras Timar <andras.timar@collabora.com>