Merge pull request fog#552 from mogotest/fix_zerigo_host_update

Fixed an issue whereby saving an existing record in Zerigo would nil out its value.

lib/fog/zerigo/models/dns/record.rb

@@ -48,7 +48,7 @@ def save
             connection.create_host(@zone.id, type, value, options)
           else
             options[:host_type] = type
-            options[:data]      = data
+            options[:data]      = value
             connection.update_host(identity, options)
           end
           merge_attributes(data.body)