sw_redlinehide_3: move assert in SwContentNode::DelFrames()

This is happening in MoveParagraph; the UpdateMergedParaForDelete will
reset the pParaPropsNode pointer so move assert below that.

Change-Id: I31069578a9bfdb05f01ea778bbe9e9ae43c865c6
diff --git a/sw/source/core/docnode/node.cxx b/sw/source/core/docnode/node.cxx
index e026e60..19cafd5 100644
--- a/sw/source/core/docnode/node.cxx
+++ b/sw/source/core/docnode/node.cxx
@@ -1366,8 +1366,6 @@ void SwContentNode::DelFrames(SwRootFrame const*const pLayout)
            {
                if (this != pMerged->pFirstNode)
                {
                    // pointer should have been updated to a different node
                    assert(this != pMerged->pParaPropsNode);
                    // SwNodes::RemoveNode iterates *backwards* - so
                    // ensure there are no more extents pointing to this
                    // node as SwFrame::InvalidatePage() will access them.
@@ -1375,6 +1373,8 @@ void SwContentNode::DelFrames(SwRootFrame const*const pLayout)
                    // because that would access deleted wrong-lists
                    sw::UpdateMergedParaForDelete(*pMerged, true,
                            *static_cast<SwTextNode*>(this), 0, Len());
                    // pointer should have been updated to a different node
                    assert(this != pMerged->pParaPropsNode);
                    if (this == pMerged->pLastNode)
                    {
                        pMerged->pLastNode = GetNodes()[GetIndex()-1]->GetTextNode();