Wait for server to be active in test_device_tagging

In test_device_tagging, we should wait for server to be
active before getting ssh_client. This testcase doesn't
fail in ci because it uses validation.connect_method = floating,
which will wait for server to be active if validatable=True
is passed in.

Besides, before get_server_ip we should call show_server,
otherwise 'addresses' is not present in the result of create_server
and so we will get:
File "/tempest/api/compute/base.py", line 387, in get_server_ip
    addresses = server['addresses'][CONF.validation.network_for_ssh]
    KeyError: 'addresses'

Change-Id: I70410c47394310795064cd9fde0b9b47ddd00982
diff --git a/tempest/api/compute/servers/test_device_tagging.py b/tempest/api/compute/servers/test_device_tagging.py
index a126fd6..d857fcb 100644
--- a/tempest/api/compute/servers/test_device_tagging.py
+++ b/tempest/api/compute/servers/test_device_tagging.py
@@ -139,6 +139,7 @@
 
         server = self.create_test_server(
             validatable=True,
+            wait_until='ACTIVE',
             validation_resources=validation_resources,
             config_drive=config_drive_enabled,
             adminPass=admin_pass,
@@ -205,6 +206,7 @@
 
         self.addCleanup(self.delete_server, server['id'])
 
+        server = self.servers_client.show_server(server['id'])['server']
         self.ssh_client = remote_client.RemoteClient(
             self.get_server_ip(server, validation_resources),
             CONF.validation.image_ssh_user,