abhishekaslk: support localtime no param function

[AbhishekASLK]

• added required changes
• postgres support localtime and you told redshift don't so i pop the token from redshift and not from postgres but not able to see why generator generating this, and if i remove localtime from RESERVED_KEYWORDS then it works, please help here

tests/dialects/test_dialect.py:34: in validate_identity
    self.assertEqual(
E   AssertionError: 'SELECT LOCALTIME' != 'SELECT "LOCALTIME"'
E   - SELECT LOCALTIME
E   + SELECT "LOCALTIME"
E   ?