Database.max_retries should be restored in get_connection_from config function

[Lan Qi song]

Under the current code base, The cfg.CONF.database.max_retries parameter would be override to "0" when starting up the ceilometer services, in this line：
https://github.com/openstack/ceilometer/blob/master/ceilometer/storage/__init__.py#L99

But the parameter is still used later in :
https://github.com/openstack/ceilometer/blob/master/ceilometer/storage/mongo/utils.py#L322

Then, the logic of reconnecting to the new master node of mongo (https://review.openstack.org/#/c/122387/) would be broken.

We can fix it by restoring the cfg.CONF.database.max_retries parameter in get_connection_from_config function.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/136964

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/136964
Committed: https://git.openstack.org/cgit/openstack/ceilometer/commit/?id=afb90e0cfc7fadae17ed9d360124e5683cb0b99a
Submitter: Jenkins
Branch: master

commit afb90e0cfc7fadae17ed9d360124e5683cb0b99a
Author: lqslan <email address hidden>
Date: Tue Nov 25 12:35:37 2014 +0800

    Database.max_retries only override on sqlalchemy side

    Currently, the max_retries parameter will be override in
    get_connection_from_config function. But it will be used
    later in safe_mongo_call function.

    Since the override of max_retries only need on sqlalchemy
    side, this patch move the override from get_connection_
    from_config to storage.impl_sqlalchemy.Connection.__init__
    and make sure max_retries can be used on mongoDB side.

    Change-Id: I83f35c886bc8b7299c1efd7297fdbc980214567f
    Closes-Bug: #1395972

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/juno
Review: https://review.openstack.org/137681

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/137681
Committed: https://git.openstack.org/cgit/openstack/ceilometer/commit/?id=d3bcd1442c816df5b09adee781892a8a5370cba4
Submitter: Jenkins
Branch: stable/juno

commit d3bcd1442c816df5b09adee781892a8a5370cba4
Author: lqslan <email address hidden>
Date: Tue Nov 25 12:35:37 2014 +0800

    Database.max_retries only override on sqlalchemy side

    Currently, the max_retries parameter will be override in
    get_connection_from_config function. But it will be used
    later in safe_mongo_call function.

    Since the override of max_retries only need on sqlalchemy
    side, this patch move the override from get_connection_
    from_config to storage.impl_sqlalchemy.Connection.__init__
    and make sure max_retries can be used on mongoDB side.

    Change-Id: I83f35c886bc8b7299c1efd7297fdbc980214567f
    Closes-Bug: #1395972
    (cherry picked from commit afb90e0cfc7fadae17ed9d360124e5683cb0b99a)