refactor the getid method in keystoneclient/base.py

Refer to a merged commit.
https://review.openstack.org/#/c/588983/

TrivialFix

Change-Id: Ie3a02843e35382dd24230e91534b6ed72846957d

keystoneclient/base.py

@@ -38,16 +38,10 @@ def getid(obj):
     Abstracts the common pattern of allowing both an object or an object's ID
     (UUID) as a parameter when dealing with relationships.
     """
-    try:
-        if obj.uuid:
-            return obj.uuid
-    except AttributeError:  # nosec(cjschaef): 'obj' doesn't contain attribute
-        # 'uuid', return attribute 'id' or the 'obj'
-        pass
-    try:
-        return obj.id
-    except AttributeError:
-        return obj
+    if getattr(obj, 'uuid', None):
+        return obj.uuid
+    else:
+        return getattr(obj, 'id', obj)
 
 
 def filter_none(**kwargs):