discard=on breaks for EFI disks

[Walter Doekes]

See #31 (comment)

[The] volume type would need to be available in the translator so it can skip setting discard=on if it sees type efidisk.

proxmove/proxmove

Lines 1860 to 1876 in 18fcd8d

 class AddDiscardOnTranslator(object): 
     def volume_properties(self, new_volume): 
         """ 
         Add "discard=on" flag to properties if possible 
         """ 
         props = super().volume_properties(new_volume) 
  
         if new_volume.storage and new_volume.storage.has_discard_support: 
             values = props.split(',') 
             name, rest = values[0], values[1:] 
             rest = [ 
                 i for i in rest if i not in ('discard=on', 'discard=off')] 
             rest.append('discard=on') 
             rest.sort() 
             props = ','.join([name] + rest) 
  
         return props 

[Walter Doekes]

This PR addesses things: #46