cloud.install: fix case statement that lead to failure

commit 7489cc5577ac7ba04475bf1f34bc7320867d9d3c broke redhat image
construction. The 'RedHatEnterpriseServer' is needed on this case
since the use of ';;&' above.
openstack-full: Remove trailing whitespaces
openstack-common: Remove twice add_rhn_channel (commented)
cloud: Fix case statement (refs: #32)

according:
https://github.com/enovance/edeploy-roles/pull/34#issuecomment-38191079
Merge pull request #34 from enovance/fix_redhat_build_fail

cloud.install: fix case statement that lead to failure