Fix after code review

Fix `#process_sql` and invalid
comment.

config/initializers/database_query_analyzers.rb

@@ -5,7 +5,6 @@ if Gitlab.dev_or_test_env? || Gitlab::Utils.to_boolean('GITLAB_ENABLE_QUERY_ANAL
   Gitlab::Database::QueryAnalyzer.instance.hook!
 
   Gitlab::Application.configure do |config|
-    # ApolloUploadServer::Middleware expects to find uploaded files ready to use
     config.middleware.use(Gitlab::Middleware::QueryAnalyzer)
   end
 end

spec/lib/gitlab/database/query_analyzer_spec.rb

@@ -126,8 +126,10 @@ RSpec.describe Gitlab::Database::QueryAnalyzer, query_analyzers: false do
     end
 
     def process_sql(sql)
-      ApplicationRecord.load_balancer.read_write do |connection|
-        described_class.instance.process_sql(sql, connection)
+      described_class.instance.within do
+        ApplicationRecord.load_balancer.read_write do |connection|
+          described_class.instance.process_sql(sql, connection)
+        end
       end
     end
   end