chore: rm unused fn

Author: youngsofun

databend-jdbc/src/main/java/com/databend/jdbc/DatabendConnection.java

@@ -790,7 +790,10 @@ private Map<String, String> setAdditionalHeaders() {
         DatabendSession session = this.getSession();
         String warehouse = null;
         if (session != null ) {
-            warehouse = session.getSettings().get("warehouse");
+            Map<String, String> settings = session.getSettings();
+            if (settings != null) {
+                warehouse = settings.get("warehouse");
+            }
         }
         if (warehouse == null && !this.driverUri.getWarehouse().isEmpty()) {
             warehouse = this.driverUri.getWarehouse();

databend-jdbc/src/main/java/com/databend/jdbc/DatabendStatement.java

@@ -165,19 +165,6 @@ private void clearCurrentResults() {
         currentResult.set(null);
     }
 
-    private void updateClientSession(QueryResults q) {
-        if (q == null) {
-            return;
-        }
-        DatabendSession session = q.getSession();
-        if (session == null) {
-            return;
-        }
-        // current query has result on update client session
-        DatabendConnection connection = this.connection.get();
-        connection.setSession(session);
-    }
-
     final boolean internalExecute(String sql, StageAttachment attachment) throws SQLException {
         clearCurrentResults();
         checkOpen();