Remove nova v2 API comments

The removed comments were for distinguishing them from nova v3 API
but now the v3 API has been removed.
So these comments are meaningless, then this patch removes them.

Change-Id: Icb51ddafcf2c06f5400f572a0862e5f67ee4dfc5
diff --git a/tempest/api/compute/base.py b/tempest/api/compute/base.py
index 1f53f9a..9ec5711 100644
--- a/tempest/api/compute/base.py
+++ b/tempest/api/compute/base.py
@@ -69,9 +69,7 @@
         cls.security_group_rules_client = cls.os.security_group_rules_client
         cls.security_groups_client = cls.os.security_groups_client
         cls.quotas_client = cls.os.quotas_client
-        # NOTE(mriedem): os-quota-class-sets is v2 API only
         cls.quota_classes_client = cls.os.quota_classes_client
-        # NOTE(mriedem): os-networks is v2 API only
         cls.networks_client = cls.os.networks_client
         cls.limits_client = cls.os.limits_client
         cls.volumes_extensions_client = cls.os.volumes_extensions_client