when generating a new one, otherwise on exporting the same table
twice to two consecutive .doc footnotes will think the second
export of the table is a level lower because it will find it
in the map and

WW8TableNodeInfo::Pointer_t WW8TableInfo::insertTableNodeInfo

does pNodeInfo->setDepth(nDepth + pNodeInfo->getDepth());
using the cached pNodeInfo depth and not a new fresh pNodeInfo of
depth 0

Change-Id: I7aa7ac6a19814910c1d19d78f04cfd9886c444c5