pg_receivewal: remove extra conn = NULL; in StreamLog

When Who What
2021-09-02 11:12:27 Daniel Gustafsson (d_gustafsson) Closed in commitfest 2021-09 with status: Committed
2021-09-02 11:12:22 Daniel Gustafsson (d_gustafsson) Added d_gustafsson as committer
2021-09-02 11:12:20 Daniel Gustafsson (d_gustafsson) Added d_gustafsson as reviewer
2021-09-01 08:57:46 Bharath Rupireddy (bharathrupireddy) Changed authors to Bharath Rupireddy (bharathrupireddy)
2021-09-01 08:57:34 Bharath Rupireddy (bharathrupireddy) Attached mail thread CALj2ACVRiNvMDHYQGiRrGs2Z9dOydfLh2MymEk9i8CSn23UtCg@mail.gmail.com
2021-09-01 08:57:34 Bharath Rupireddy (bharathrupireddy) Created patch record