Import of "Text In ++" is broken

Created by: portnov

Problem statement

https://gist.github.com/portnov/582de3f84a99210493882393a9137ef9

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ERROR: test_import_examples (tree_import_tests.ExamplesImportTest) (file='5.Sverchok_Spread.json')
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Traceback (most recent call last):
  File "/home/portnov/.config/blender/2.79/scripts/addons/sverchok-master/tests/tree_import_tests.py", line 66, in test_import_examples
    import_tree(new_tree, path)
  File "/home/portnov/.config/blender/2.79/scripts/addons/sverchok-master/utils/sv_IO_panel_tools.py", line 729, in import_tree
    generate_layout(fullpath, nodes_json)
  File "/home/portnov/.config/blender/2.79/scripts/addons/sverchok-master/utils/sv_IO_panel_tools.py", line 711, in generate_layout
    place_frames(ng, nodes_json, name_remap)
  File "/home/portnov/.config/blender/2.79/scripts/addons/sverchok-master/utils/sv_IO_panel_tools.py", line 638, in place_frames
    ng.nodes[finalize(node_name)].parent = ng.nodes[finalize(parent)]
KeyError: 'bpy_prop_collection[key]: key "Text in+.001" not found'

Steps to reproduce

1. Load example "5.Sverchok_Spread.json"
2. replace Text In nodes with Text In ++
3. Export result to json again
4. Try to import it again (from test or manually from blender, doesn't matter)

Expected result

Loaded node tree

Actual result

Exception

Sverchok version

git master