bnc#887225: OOXML import: Correctly apply table style for lastRow.

nMaxColumn and nMaxRow are indexes, so use size() - 1.

Change-Id: I20055e55cf2464710fe553fb8067bad13a339084
(cherry picked from commit 47645734c350f244b4a5642a709132ca1b7dc75d)
Reviewed-on: https://gerrit.libreoffice.org/10331
Reviewed-by: Andras Timar <andras.timar@collabora.com>
Tested-by: Andras Timar <andras.timar@collabora.com>