[issue27881] Fix possible bugs when setting sqlite3.Connection.isolation_level

[Serhiy Storchaka]

Changes by Serhiy Storchaka <storchaka+cpython at gmail.com>:


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assignee:  -> serhiy.storchaka
stage:  -> patch review

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Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue27881>
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