fix dsn builder

Author: lesnik512

db_retry/dsn.py

@@ -21,7 +21,10 @@ def build_db_dsn(
     return parsed_db_dsn.set(
         database=database_name,
         drivername=drivername,
-        query={"target_session_attrs": "prefer-standby" if use_replica else "read-write"} | db_dsn_query,
+        query=db_dsn_query
+        | {
+            "target_session_attrs": "prefer-standby" if use_replica else "read-write",
+        },
     )