create_db_entry_for_new_instance did not call sgh for default

When an instance is launched create_db_entry_for_new_instance() is
called which calls self.db.instance_create(). Then,
db.security_group_ensure_default() is called which creates the
default security group entry in the nova db. Though the sgh handler was
not called. Alternatively, if any nova secgroup-* call is made the sgh
is called which creates the default security group. This patch adds
a call to ensure_default() before db.instance_create() so the sgh
is called. Fixes a case missed in  bug 1050982

Change-Id: I9649b5ef026ca18a55abfb66e87fd0e358eba6f2

nova/compute/api.py

@@ -732,6 +732,10 @@ def create_db_entry_for_new_instance(self, context, instance_type, image,
         self._populate_instance_shutdown_terminate(instance, image,
                                                    block_device_mapping)
 
+        # ensure_default security group is called before the instance
+        # is created so the creation of the default security group is
+        # proxied to the sgh.
+        self.security_group_api.ensure_default(context)
         instance = self.db.instance_create(context, instance)
 
         self._populate_instance_for_bdm(context, instance,