Hide rack profiler by default

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

config/initializers/6_rack_profiler.rb

@@ -4,4 +4,5 @@ if Rails.env == 'development'
   # initialization is skipped so trigger it
   Rack::MiniProfilerRails.initialize!(Rails.application)
   Rack::MiniProfiler.config.position = 'right'
+  Rack::MiniProfiler.config.start_hidden = true
 end