Merge branch 'ajk-query-recorder' into 'master'

Make debug logs more greppable

See merge request gitlab-org/gitlab!31557

spec/support/helpers/query_recorder.rb

@@ -19,7 +19,9 @@ module ActiveRecord
 
     def show_backtrace(values)
       Rails.logger.debug("QueryRecorder SQL: #{values[:sql]}")
-      Gitlab::BacktraceCleaner.clean_backtrace(caller).each { |line| Rails.logger.debug("   --> #{line}") }
+      Gitlab::BacktraceCleaner.clean_backtrace(caller).each do |line|
+        Rails.logger.debug("QueryRecorder backtrace:  --> #{line}")
+      end
     end
 
     def get_sql_source(sql)