fixes #1897: the "version" field will be updated even when versions are merged

app/models/artist.rb

@@ -145,7 +145,8 @@ class Artist < ActiveRecord::Base
         :is_active => is_active,
         :is_banned => is_banned,
         :other_names => other_names,
-        :group_name => group_name
+        :group_name => group_name,
+        :version => versions.where("id <> ?", prev.id).maximum(:version) || 1
       )
     end