DOCX import: ignore <w:tblpPr> in shape text

Floating tables are kind of anchored objects, which are not supported in
shape text by Word, so we should ignore their flotation on import as
well.

Note that there is no need for a setIsInShape(false) in
PopShapeContext() as we pop the whole table manager from the stack
anyway.

Change-Id: Ie9e88d2c83c0c34a01922e6e89f69f6089585b4b