Delete Volume on instance delete & is appearing twice if we boot instance from volume tab under horizon dashboard

Issue

• Delete Volume on instance delete is appears twice

  Sometimes the volume is not predefined, which should be always there otherwise the option to launch an instance from a volume makes no sense. 
  

  After pressing F5 (refresh) the volume will be predefined. The double button is always there.
  

• Expected results

  There should be one `Delete Volume on instance delete` button.
  

  volume should alway be predefined we select volume as source.