Remove scenario.manager.rebuild_server

rebuild_server in scenario.manager is never used, besides,
it doesn't do much things so is not expected to be widely
used by scenario testcases in the future, so this is to
remove it.

Change-Id: I1dddf7d57c91a849403e77e4cc7595ba48140d00
diff --git a/tempest/scenario/manager.py b/tempest/scenario/manager.py
index 4f7c090..26e1451 100644
--- a/tempest/scenario/manager.py
+++ b/tempest/scenario/manager.py
@@ -504,24 +504,6 @@
         waiters.wait_for_volume_resource_status(self.volumes_client,
                                                 volume['id'], 'available')
 
-    def rebuild_server(self, server_id, image=None,
-                       preserve_ephemeral=False, wait=True,
-                       rebuild_kwargs=None):
-        if image is None:
-            image = CONF.compute.image_ref
-
-        rebuild_kwargs = rebuild_kwargs or {}
-
-        LOG.debug("Rebuilding server (id: %s, image: %s, preserve eph: %s)",
-                  server_id, image, preserve_ephemeral)
-        self.servers_client.rebuild_server(
-            server_id=server_id, image_ref=image,
-            preserve_ephemeral=preserve_ephemeral,
-            **rebuild_kwargs)
-        if wait:
-            waiters.wait_for_server_status(self.servers_client,
-                                           server_id, 'ACTIVE')
-
     def ping_ip_address(self, ip_address, should_succeed=True,
                         ping_timeout=None, mtu=None):
         timeout = ping_timeout or CONF.validation.ping_timeout