bareos-fd-postgres: properly close database connection

[lluuaapp]

This will properly close the database connection after a Postgres WAL backup was made. As far as I could see a call to close() is completely missing in the current code. As the the connection may already been closed I put it in a try/except to ignore all errors that may occur.

On my test system this prevents the PostgreSQL server to log

unexpected EOF on client connection with an open transaction

every backup.

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[arogge]

Hi,
thanks for the quick update. You provided a great improvement.
I still have to try it out and I'm not sure I'll find the time to do this today.

[arogge]

Looks great! Thanks you very much.