[MERGE][#334114][1.13] Fix bogus 'Source format does not support stacking' warning when pushing to smart server

[James Westby]

James Westby has voted approve.
Status is now: Approved


For details, see: 
http://bundlebuggy.aaronbentley.com/project/bzr/request/%3C20090311070718.GA23314%40steerpike.home.puzzling.org%3E
Project: Bazaar