Handle user already in group

src/phicli

@@ -98,6 +98,10 @@ def addtogroup(uid, gcn):
         print('Group {} not found'.format(gcn))
         return
 
+    if uid in group['members']:
+        print('User {} is already in group {}'.format(uid, gcn))
+        return
+
     add_group_member(client, group, user)