Fix eternal lock when hive metastore down during request with lock

[anton-kutuzov]

Description

Added unlock for case when exception occur during get connection to metastore if we don't unlock this lock, it stills in database and next locks will wait it, this lock have never removed as request finished with exception.
Without fix the one way to unlock is remove raw manually in database

Release notes

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## Section
* Fix some things. ({issue}`issuenumber`)

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[electrum]

Thanks!