Merge branch 'fix-scalar-output' into 'master'

Fix scalar output shape bug in operator.jinja2

See merge request !1083

mace/python/tools/operator.jinja2

@@ -83,30 +83,35 @@ void CreateOperator{{i}}(mace::OperatorDef *op) {
   arg->set_s({{ arg.s.decode('utf-8')|tojson }});
   {%- endif %}
 
+  {% if arg.floats|length > 0 %}
     arg->mutable_floats()->Reserve({{ arg.floats|length }});
     {% for float_value in arg.floats %}
     arg->add_floats({{ float_value }});
     {% endfor %}
+  {% endif %}
+
+  {% if arg.ints|length > 0 %}
     arg->mutable_ints()->Reserve({{ arg.ints|length }});
     {% for int_value in arg.ints %}
     arg->add_ints({{ int_value }});
     {% endfor %}
+  {% endif %}
 
   {% endfor %}
 
   {% if net.op[i].output_shape|length > 0 %}
   op->mutable_output_shape()->Reserve({{ net.op[i].output_shape|length }});
-  mace::OutputShape * output_shape = nullptr;
   {% for shape in net.op[i].output_shape %}
   {% if shape.dims|length > 0 %}
-  output_shape = op->add_output_shape();
-
+  {
+      mace::OutputShape *output_shape = op->add_output_shape();
       output_shape->mutable_dims()->Reserve({{ shape.dims|length }});
       {% for dim in shape.dims %}
       output_shape->add_dims({{ dim }});
       {% endfor %}
-
+  }
   {% endif %}
+
   {% endfor %}
   {% endif %}