Remove unused code + Increase frequeuncy of host heartbeat update

ucloud/api/main.py

@@ -19,15 +19,6 @@ from . import schemas
 from .helper import generate_mac, mac2ipv6
 
 
-def get_parent(obj, attr):
-    parent = getattr(obj, attr)
-    child = parent
-    while parent is not None:
-        child = parent
-        parent = getattr(parent, attr)
-    return child
-
-
 logger = logging.getLogger(__name__)
 
 app = Flask(__name__)