Remove unused import

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extra : histedit_source : 52e8d496515f65df5c0154d9ab0d3dc5c3e8e44f
Fix test failing in Python 3.x

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extra : histedit_source : a0db24b53f5429b770654e01831b2b41d61b5644
Test expected warning from wait_for_occupied_port()

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extra : histedit_source : 743c82511dde6fc7b06a9ce318c11413a74d8042