also test each_hash.next raises when closed

Author: kch

test/test_integration_resultset.rb

@@ -147,6 +147,7 @@ def test_close
     assert_raise(SQLite3::Exception) { result.reset }
     assert_raise(SQLite3::Exception) { result.next }
     assert_raise(SQLite3::Exception) { result.each.next }
+    assert_raise(SQLite3::Exception) { result.each_hash.next }
     assert_raise(SQLite3::Exception) { result.close }
     assert_raise(SQLite3::Exception) { result.types }
     assert_raise(SQLite3::Exception) { result.columns }