fix sparse grad merge on pserver

python/paddle/fluid/transpiler/distribute_transpiler.py

@@ -1287,8 +1287,6 @@ class DistributeTranspiler(object):
                 inputs={"X": vars2merge},
                 outputs={"Out": merged_var},
                 attrs={"use_mkldnn": False})
-            # TODO(panyx0718): What if it's SELECTED_ROWS.
-            if not merged_var.type == core.VarDesc.VarType.SELECTED_ROWS:
             optimize_block.append_op(
                 type="scale",
                 inputs={"X": merged_var},