fix(db): work around dropped connection issue in pdns (https://github.com/PowerDNS/pdns/issues/3824)

db/51-server.cnf

@@ -9,3 +9,5 @@ binlog_format=ROW
 log-basename=nsmaster
 binlog-do-db=pdnsmaster
 expire_logs_days        = 10
+
+wait_timeout = 28800