Refer to correct array index in chunkAnchorPoint

Doesn't seem to make a difference in the "usual"
use case, but at least for Put on Path with the
Objects Dialog open, there is a difference.

Fix inbox#421

Cherry-pick from f09728fd (1.0alpha)

src/libnrtype/Layout-TNG-OutIter.cpp

@@ -291,13 +291,13 @@ Geom::Point Layout::chunkAnchorPoint(iterator const &it) const
 
     Alignment alignment = _paragraphs[_lines[_chunks[chunk_index].in_line].in_paragraph].alignment;
     if (alignment == LEFT || alignment == FULL)
-        return Geom::Point(_chunks[chunk_index].left_x, _lines[chunk_index].baseline_y);
+        return Geom::Point(_chunks[chunk_index].left_x, _lines[_chunks[chunk_index].in_line].baseline_y);
 
     double chunk_width = _getChunkWidth(chunk_index);
     if (alignment == RIGHT)
-        return Geom::Point(_chunks[chunk_index].left_x + chunk_width, _lines[chunk_index].baseline_y);
+        return Geom::Point(_chunks[chunk_index].left_x + chunk_width, _lines[_chunks[chunk_index].in_line].baseline_y);
     //centre
-    return Geom::Point(_chunks[chunk_index].left_x + chunk_width * 0.5, _lines[chunk_index].baseline_y);
+    return Geom::Point(_chunks[chunk_index].left_x + chunk_width * 0.5, _lines[_chunks[chunk_index].in_line].baseline_y);
 }
 
 Geom::Rect Layout::characterBoundingBox(iterator const &it, double *rotation) const