Description of problem:
Failed to deploy additional host with NFS storage
Problem in this check under plugins/ovirt-hosted-engine-setup/storage/storage.py
if (
                    domain_info and
                    'remotePath' in domain_info and
                    'type' in domain_info and
                    domain_info['type'] in (
                        ohostedcons.VDSMConstants.NFS_DOMAIN,
                        ohostedcons.VDSMConstants.GLUSTERFS_DOMAIN,
                    ) and
                    self._removeNFSTrailingSlash(
                        domain_info['remotePath']
                    ) == self._removeNFSTrailingSlash(
                        self.environment[
                            ohostedcons.StorageEnv.STORAGE_DOMAIN_CONNECTION
                        ]
                    )
                ):
domain_info['type'] = 'NFS'
and ohostedcons.VDSMConstants.NFS_DOMAIN = 1
so I believe it enough to change constant under ohostedcons.VDSMConstants

Version-Release number of selected component (if applicable):
ovirt-hosted-engine-setup-1.3.0-0.0.master.20150401110307.git9665976.el7.noarch

How reproducible:
Always

Steps to Reproduce:
1. Deploy HE environment on host
2. Try to add additional host to HE environment
3. Deployment just not see that this additional host and try to add host like first one

Actual results:
Deployment just not see that this additional host and try to add host like first one

Expected results:
Deployment must recognize that storage not empty and give dialog with additional host

Additional info: