Merge pull request #2134 from ogckw/master

Fix #2129 EC2 tag should raise ClientError when resource is empty

moto/ec2/models.py

@@ -134,6 +134,8 @@ def utc_date_and_time():
 
 
 def validate_resource_ids(resource_ids):
+    if not resource_ids:
+        raise MissingParameterError(parameter='resourceIdSet')
     for resource_id in resource_ids:
         if not is_valid_resource_id(resource_id):
             raise InvalidID(resource_id=resource_id)