Replace `is instance or` with a tuple of types.

If I'm reading this correctly, this will work on Python 3, but not Python 2.  Namely that in Python 2, str = bytes, and in Python 3, str != bytes, (str = unicode).  In either case, RqlBinary inherits from bytes.

This will return False for all cases (str/bytes, unicode, and RqlBinary) on Python 2, when it should return True for str/bytes and RqlBinary.