Update citations of Internet RFCs

For example, RFC 822 has been obsoleted by RFC 2822, which in
turn has been obsoleted by RFC 5322.
* doc/emacs/ack.texi, doc/lispref/os.texi:
* doc/misc/emacs-mime.texi, doc/misc/gnus-coding.texi:
* doc/misc/gnus.texi, doc/misc/sc.texi:
* lisp/calendar/parse-time.el, lisp/gnus/gnus-cite.el:
* lisp/gnus/gnus-util.el, lisp/gnus/message.el:
* lisp/gnus/mm-bodies.el, lisp/gnus/nnrss.el:
* lisp/mail/feedmail.el, lisp/mail/ietf-drums.el:
* lisp/mail/mail-extr.el, lisp/mail/mail-utils.el:
* lisp/mail/mailclient.el, lisp/mail/mailheader.el:
* lisp/mail/rfc2047.el, lisp/mail/rfc822.el, lisp/mail/rmail.el:
* lisp/mail/sendmail.el, lisp/mail/smtpmail.el:
* lisp/mail/supercite.el, lisp/mh-e/mh-e.el:
* lisp/mh-e/mh-utils.el, lisp/net/imap.el:
* lisp/net/newst-backend.el, lisp/org/org-id.el:
* lisp/ps-samp.el, lisp/simple.el, lisp/url/url-util.el:
Update RFC citations.
1 job for emacs-26 in 30 minutes and 14 seconds (queued for 1 second)
Status Job ID Name Coverage
  Test
passed #835
test

00:30:14