This 75-byte horror creates 2 nested tables, where one SwTableBox is in
the SwTableLine of the inner SwTable but in the SwSortBoxes of the outer
table, which is of course invalid.

The root cause is that in SwHTMLParser::SplitAttrTab(), we move the
m_pPam backward once and forward twice, moving it ouside the inner
table.

Change-Id: I63f6508afe1270ccdeb05da6f222b0aba5259889