max_connections option no longer works

I deployed cs:trusty/postgresql-38 with this config:

postgresql-test-charm-config:
    max_connections: 341
    max_prepared_transactions: 342

The values are represented in the juju get output:
  max_connections:
    description: |
      DEPRECATED. Use extra_pg_conf. Maximum number of connections to allow to the PG database
    type: int
    value: 341
...
  max_prepared_transactions:
    description: |
      DEPRECATED. Use extra_pg_conf. Maximum number of prepared two phase commit transactions, waiting to be committed. Defaults to 0. as using two phase commit without a process to monitor and resolve lost transactions is dangerous.
    type: int
    value: 342

But only max_prepared_transactions was actually set to its value in the actual postgresql config file:
oot@node-7:~# cat /etc/postgresql/9.3/main/postgresql.conf |grep -E "max_(connections|prepared_transactions)"
# juju # max_connections = 100 # (change requires restart)
# Note: Increasing max_connections costs ~400 bytes of shared memory per
#max_prepared_transactions = 0 # zero disables the feature
# Note: Increasing max_prepared_transactions costs ~600 bytes of shared memory
# It is not advisable to set max_prepared_transactions nonzero unless you
# max_locks_per_transaction * (max_connections + max_prepared_transactions)
max_prepared_transactions = 342
max_connections = 100

I got a few warnings in the juju logs:
2016-01-15 11:20:31 WARNING juju-log max_connectionsDeprecated configuration settings in use: {}, max_prepared_transactions
2016-01-15 11:20:37 WARNING juju-log max_connectionsDeprecated configuration settings in use: {}, max_prepared_transactions
2016-01-15 11:20:42 WARNING juju-log max_connectionsDeprecated configuration settings in use: {}, max_prepared_transactions
2016-01-15 11:20:48 WARNING juju-log max_connectionsDeprecated configuration settings in use: {}, max_prepared_transactions