Set keystone http scheme correctly

When the management and public network ranges differ the http scheme in
the dashboard config file for keystone omit the http or https portion of
the config option.  This sets it.

Resolves rcbops/chef-cookbooks/Issue#753

(cherry picked from commit e9ff78871faa54e7053581881995e77b478cb9b0)
Merge pull request #159 from claco/issue-753

Merged automatically by jenkins after successful build test