fixed returning correct information about execution result and resultset

Author: chernser

jdbc-v2/src/main/java/com/clickhouse/jdbc/WriterStatementImpl.java

@@ -78,6 +78,16 @@ public int executeUpdate() throws SQLException {
         return (int) this.executeLargeUpdate();
     }
 
+    @Override
+    public boolean getMoreResults() throws SQLException {
+        return false; // no result sets
+    }
+
+    @Override
+    public ResultSet getResultSet() throws SQLException {
+        return null; // no result set
+    }
+
     @Override
     public long executeLargeUpdate() throws SQLException {
         checkClosed();
@@ -268,7 +278,7 @@ public void clearParameters() throws SQLException {
     @Override
     public boolean execute() throws SQLException {
         executeLargeUpdate();
-        return true;
+        return false; // no result set
     }
 
     @Override