FIX: config was moved to a global

FIX: config was moved to a global

This code stopped working a while ago.

Fixes: #477

diff --git a/lib/mini_profiler/client_settings.rb b/lib/mini_profiler/client_settings.rb
index 058d661..8de1318 100644
--- a/lib/mini_profiler/client_settings.rb
+++ b/lib/mini_profiler/client_settings.rb
@@ -94,8 +94,8 @@ module Rack
           begin
             @allowed_tokens ||= @store.allowed_tokens
           rescue => e
-            if @config.storage_failure != nil
-              @config.storage_failure.call(e)
+            if MiniProfiler.config.storage_failure != nil
+              MiniProfiler.config.storage_failure.call(e)
             end
           end
 

GitHub sha: d4a3e77e