Remove database config from staging.py

This configuration connects to pgbouncer, which we are no longer using. Our RDS Proxy config requires secrets which don't belong in ctlsettings, and this configuration is now in local_settings.py in salt, for the time being.

ctlsettings/staging.py

@@ -18,18 +18,6 @@ def common(**kwargs):
     DEBUG = False
     STAGING_ENV = True
 
-    DATABASES = {
-        'default': {
-            'ENGINE': 'django.db.backends.postgresql',
-            'NAME': project,
-            'HOST': '',
-            'PORT': 6432,
-            'USER': '',
-            'PASSWORD': '',
-            'ATOMIC_REQUESTS': True,
-        }
-    }
-
     STATSD_PREFIX = project + "-staging"
 
     MEDIA_ROOT = '/var/www/' + project + '/uploads/'