Fix host status grep bug and Remove connection_pool argument

Host status returned the wrong output as the "OS-EXT-SRV-ATTR:host"
pattern appears twice in the "openstack server show" output.
The argument connection_pool is deprecated and is not needed.

Change-Id: Ib107e0bad8084bdf6f77689f112bde04bdb97543
Signed-off-by: Umar Farooq <umar.farooq@neclab.eu>