Fix an HA test script: this failed when there was only a single host in the pool.
Fix an HA test script: this failed when there was only a single host in the pool.

Signed-off-by: David Scott <63c9eb0ea83039690fefa11afe17873ba8278a56@eu.citrix.com>

johnelse/xcp-rrdd,robhoes/squeezed,sharady/xcp-networkd,simonjbeaumont/xcp-rrdd,simonjbeaumont/xcp-rrdd,djs55/xcp-rrdd,koushikcgit/xcp-networkd,djs55/xcp-networkd,djs55/xcp-networkd,koushikcgit/xcp-rrdd,djs55/squeezed,koushikcgit/xcp-networkd,sharady/xcp-networkd,koushikcgit/xcp-rrdd,koushikcgit/xcp-rrdd,djs55/xcp-rrdd,johnelse/xcp-rrdd