function env.get_db_cnx() is no longer available with trac 1.2

[rothan@…]

I've running trac 1.2 with the AnnouncerPlugin (trunk, rev 16171) and get the following errors:

The first one occurs when a message should be send via email:

2017-01-09 14:45:00,158 Trac[api] ERROR: AnnouncementSystem failed.
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/announcer/api.py", line 576, in _real_send
    evt)
  File "/usr/lib/python2.7/dist-packages/announcer/distributors/mail.py", line 278, in distribute
    address = resolver.get_address_for_name(name, authed)
  File "/usr/lib/python2.7/dist-packages/announcer/resolvers.py", line 58, in get_address_for_name
    db = self.env.get_db_cnx()
AttributeError: 'Environment' object has no attribute 'get_db_cnx'

the second one occurs when a user visits his user preferences, Announcement tab.

File "/usr/lib/python2.7/dist-packages/trac/web/main.py", line 613, in _dispatch_request
  dispatcher.dispatch(req)
File "/usr/lib/python2.7/dist-packages/trac/web/main.py", line 253, in dispatch
  resp = chosen_handler.process_request(req)
File "/usr/lib/python2.7/dist-packages/trac/prefs/web_ui.py", line 109, in process_request
  chosen_provider.render_preference_panel(req, panel_id)
File "/usr/lib/python2.7/dist-packages/announcer/pref.py", line 87, in render_preference_panel
  for name, label, template, data in self._get_boxes(req):
File "/usr/lib/python2.7/dist-packages/announcer/pref.py", line 82, in _get_boxes
  boxname))
File "/usr/lib/python2.7/dist-packages/announcer/resolvers.py", line 107, in render_announcement_preference_box
  specified = self.setting.get_user_setting(req.session.sid)[1] or ''
File "/usr/lib/python2.7/dist-packages/announcer/util/settings.py", line 51, in get_user_setting
  db = self.env.get_db_cnx()

[Jun Omae]

See #12120 and #12982.