Fix get_changes for empty versions.
Fix get_changes for empty versions.

ujdhesa/unisubs,norayr/unisubs,pculture/unisubs,ujdhesa/unisubs,ofer43211/unisubs,ReachingOut/unisubs,eloquence/unisubs,wevoice/wesub,wevoice/wesub,wevoice/wesub,norayr/unisubs,eloquence/unisubs,pculture/unisubs,ujdhesa/unisubs,ReachingOut/unisubs,eloquence/unisubs,ReachingOut/unisubs,norayr/unisubs,ofer43211/unisubs,pculture/unisubs,wevoice/wesub,norayr/unisubs,ofer43211/unisubs,ujdhesa/unisubs,pculture/unisubs,ofer43211/unisubs,eloquence/unisubs,ReachingOut/unisubs