usage: manila-manage share update_host --currenthost CURRENTHOST
--newhost NEWHOST
[--force FORCE]
--currenthost CURRENTHOST Current share host name.
--newhost NEWHOST New share host name.
--force FORCE Ignore validations.
A fully qualified host string is of the format
'HostA@BackendB#PoolC'. The command allows making
substring modifications to update the host or the
host and backend. To avoid making gratuitous changes,
the complete host string must be specified.
Change-Id: I0f30ab6135c8c438860341cc68b512311e9c4711