fdo#45724 improve WW8 textbox export

If there is no default value, but there is a current one, export that
instead.

Change-Id: I01af5cfa641b061b0aeb959e579bca66340781e9

oox/source/ole/axcontrol.cxx

@@ -1709,6 +1709,9 @@ void AxTextBoxModel::convertFromProperties( PropertySet& rPropSet, const Control
     if ( rPropSet.getProperty( bRes,  PROP_HideInactiveSelection ) )
         setFlag( mnFlags, AX_FLAGS_HIDESELECTION, bRes );
     rPropSet.getProperty( maValue, ( mbAwtModel ? PROP_Text : PROP_DefaultText ) );
+    if (maValue.isEmpty() && !mbAwtModel)
+        // No default value? Then try exporting the current one.
+        rPropSet.getProperty( maValue, PROP_Text);
     sal_Int16 nTmp(0);
     if ( rPropSet.getProperty( nTmp, PROP_MaxTextLen ) )
         mnMaxLength = nTmp;