fix lost default volume_type after creating LVM volume

Author: mxey

lib/fog/libvirt/models/compute/volume.rb

@@ -53,6 +53,13 @@ def wipe
           service.volume_action key, :wipe
         end
 
+        def reload
+          super
+
+          # Restore lost defaults
+          self.format_type ||= defaults[:format_type]
+        end
+
         # Clones this volume to the name provided
         def clone(name)
           new_volume      = self.dup