add glanceclient timeout option

[Edward Hope-Morley]

Glanceclient supports a default timeout of 600 seconds for http/https connection. This may or may not be appropriate so we need to add a config option to allow user to specify a different timeout value.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/39522

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/39522
Committed: http://github.com/openstack/cinder/commit/e5a4c752290fb35572dc5990c1688e5f9d49051f
Submitter: Jenkins
Branch: master

commit e5a4c752290fb35572dc5990c1688e5f9d49051f
Author: Edward Hope-Morley <email address hidden>
Date: Wed Jul 31 17:26:32 2013 +0100

    Added glance_request_timeout config option.

    The glanceclient supports a timeout for http/https
    connections but this is not configurable in cinder.
    This patch adds a glance_request_timeout
    option to cinder.conf. If unset, None is applied thus
    allowing glanceclient to use its default value (600).

    Change-Id: Ic689ecb5d5ee8257964b341b5a7980d5733343dc
    Fixes: bug #1206992
    Co-authored-by: Takahiro Shida <email address hidden>