bf: fix mongo counter

[alexanderchan-scality]

Use of Object object instead of the string object for validating typeof lead to counter not being triggered.

[bert-e]

Hello alexanderchan-scality,

My role is to assist you with the merge of this
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Status report is not available.

[bert-e]

Waiting for approval

The following approvals are needed before I can proceed with the merge:

• 2 peers

[ironman-machine]

PR has been updated. Reviewers, please be cautious.

[bert-e]

In the queue

The changeset has received all authorizations and has been added to the
relevant queue(s). The queue(s) will be merged in the target development
branch(es) as soon as builds have passed.

The changeset will be merged in:

• ✔️ development/8.0

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[bert-e]

I have successfully merged the changeset of this pull request
into targetted development branches:

• ✔️ development/8.0

Please check the status of the associated issue ZENKO-580.

Goodbye alexanderchan-scality.