Commit fe444d1f (fdo#62536: sw: fix
AutoCorrect bold/underline on existing AUTOFMT, 2013-06-20) adds an
empty inet format hint on the text node during autocorrection, on export
we can safely ignore that to provide well-formed output.

Change-Id: Iafae941a13e29dcc7d8b4bade5ce94a486b59638