Remove setUpClass added after cleanup

After the cleanup of setUpClass a new one managed to sneak
in. Removing it now, and enforcing the hacking rule in next
patchset.

Change-Id: If53b3a7d299f01f7c45739f5b2f023fbdb73aa45
diff --git a/tempest/api/compute/security_groups/test_security_group_rules.py b/tempest/api/compute/security_groups/test_security_group_rules.py
index 901c377..bb8b3e1 100644
--- a/tempest/api/compute/security_groups/test_security_group_rules.py
+++ b/tempest/api/compute/security_groups/test_security_group_rules.py
@@ -27,13 +27,9 @@
         super(SecurityGroupRulesTestJSON, cls).resource_setup()
         cls.client = cls.security_groups_client
         cls.neutron_available = CONF.service_available.neutron
-
-    @classmethod
-    def setUpClass(self):
-        super(SecurityGroupRulesTestJSON, self).setUpClass()
-        self.ip_protocol = 'tcp'
-        self.from_port = 22
-        self.to_port = 22
+        cls.ip_protocol = 'tcp'
+        cls.from_port = 22
+        cls.to_port = 22
 
     @test.attr(type='smoke')
     @test.services('network')