Remove unused configurations

The following configurations are not used.

o host_state_interval=120
    This configuration was added in the following commit.

      commit 6e6b4ad411
      Author: Gary Kotton <gkotton@vmware.com>
      Date:   Wed Dec 4 05:36:21 2013 -0800

          Image cache: move all of the variables to a common place

    But it can not be seen to be using to me.

o lvm_snapshot_size=1000
    This configuration was renamed from 'libvirt_lvm_snapshot_size'
    in the following commit.

      commit 25a7de2054
      Author: Michael Still <mikal@stillhq.com>
      Date:   Wed Nov 6 15:25:05 2013 +1100

          Move flags in libvirt's imagebackend to the libvirt group

    'libvirt_lvm_snapshot_size' was removed in the following commit.

      commit 8c985874c7
      Author: Vladan Popovic <vpopovic@redhat.com>
      Date:   Thu Oct 17 07:41:20 2013 -0400

          Remove unnecessary steps for cold snapshots

Change-Id: Ic2b45a3330769ab7c3c5a92ea38bd9d0f9ef519a

etc/nova/nova.conf.sample

@@ -701,10 +701,6 @@
 # updates (integer value)
 #heal_instance_info_cache_interval=60
 
-# Interval in seconds for querying the host status (integer
-# value)
-#host_state_interval=120
-
 # Interval in seconds for reclaiming deleted instances
 # (integer value)
 #reclaim_instance_interval=0
@@ -2876,10 +2872,6 @@
 # Deprecated group/name - [DEFAULT]/libvirt_sparse_logical_volumes
 #sparse_logical_volumes=false
 
-# The amount of storage (in megabytes) to allocate for LVM
-# snapshot copy-on-write blocks. (integer value)
-#lvm_snapshot_size=1000
-
 # The RADOS pool in which rbd volumes are stored (string
 # value)
 # Deprecated group/name - [DEFAULT]/libvirt_images_rbd_pool

nova/compute/manager.py

@@ -130,9 +130,6 @@ interval_opts = [
                default=60,
                help="Number of seconds between instance info_cache self "
                         "healing updates"),
-    cfg.IntOpt('host_state_interval',
-               default=120,
-               help='Interval in seconds for querying the host status'),
     cfg.IntOpt('reclaim_instance_interval',
                default=0,
                help='Interval in seconds for reclaiming deleted instances'),

nova/virt/libvirt/imagebackend.py

@@ -64,11 +64,6 @@ __imagebackend_opts = [
                      ' if this flag is set to True.',
                 deprecated_group='DEFAULT',
                 deprecated_name='libvirt_sparse_logical_volumes'),
-    cfg.IntOpt('lvm_snapshot_size',
-               default=1000,
-               help='The amount of storage (in megabytes) to allocate for LVM'
-                    ' snapshot copy-on-write blocks.',
-               deprecated_group='DEFAULT'),
     cfg.StrOpt('images_rbd_pool',
                default='rbd',
                help='The RADOS pool in which rbd volumes are stored',