This patch alows specifiying a deviation of the swift default port 8080 with
variable SWIFT_DEFAULT_BIND_PORT. The created endpoints in keystone for
object-store and the backup_swift_url in cinder.conf will use variable
SWIFT_DEFAULT_BIND_PORT instead of the fixed port 8080.
Change-Id: I47bbcf77368c430718fb8f29b7de1ff305e64422
Closes-Bug: #1489767