cluster_name opt for vSphere driver is MultiStrOpt and currently
users are not able to set multiple values from localrc. This is
fixed by using iniset_multiline function.
Thus, new usage would be :
VMWAREAPI_CLUSTER='cluster1 cluster2 cluster3'
where c1, c2, c3 are the name of the clusters
Change-Id: Ie0f3a48614e6134d849050754932a3613363ce66
1a3c3734b2