Extra quote_all_identifiers in _dumpOptions

Hello hackers,

While working on pg_dump I noticed the extra quote_all_identifiers in 
_dumpOptions struct. I attached the patch.

It came from refactoring by 0eea8047bf. There is also a discussion:
https://www.postgresql.org/message-id/CACw0%2B13ZUcXbj9GKJNGZTkym1SXhwRu28nxHoJMoX5Qwmbg_%2Bw%40mail.gmail.com

Initially the patch proposed to use quote_all_identifiers of 
_dumpOptions. But then everyone came to a decision to use global 
quote_all_identifiers from string_utils.c, because fmtId() uses it.

-- 
Arthur Zakirov
Postgres Professional: http://www.postgrespro.com
Russian Postgres Company