Make vapp_storage_profile optional
Make vapp_storage_profile optional

Otherwise we would break people who have not set this already.
[#102693284](https://www.pivotaltracker.com/story/show/102693284)

cloudfoundry-incubator/bosh-vcloud-cpi-release,cloudfoundry-incubator/bosh-vcloud-cpi-release,cloudfoundry-incubator/bosh-vcloud-cpi-release