Default tags overrided user's tags

[fffx]

When I use InfluxDB::Rails.instrument in a background process, I would like to override the default location

InfluxDB::Rails.instrument "expensive_operation", tags: {location: "Foo#bar }, values: { } do
  expensive_operation
end

but the location tag will override by raw. Could consider change config.tags_middleware.call(tags.merge(default_tags))
to config.tags_middleware.call(default_tags.merge(tags)) ?

[ChrisBr]

I think this makes sense. I can change it.