Fix backtrace silencer for load balancing

This restores the previous behaviour of silencing load balancing lines
in dev/test. This was missed in the move of DB load balancing to Core

config/initializers/backtrace_silencers.rb

@@ -4,7 +4,7 @@ Rails.backtrace_cleaner.remove_silencers!
 
 # This allows us to see the proper caller of SQL calls in {development,test}.log
 if (Rails.env.development? || Rails.env.test?) && Gitlab.ee?
-  Rails.backtrace_cleaner.add_silencer { |line| %r(^ee/lib/gitlab/database/load_balancing).match?(line) }
+  Rails.backtrace_cleaner.add_silencer { |line| %r(^lib/gitlab/database/load_balancing).match?(line) }
 end
 
 Rails.backtrace_cleaner.add_silencer { |line| !Gitlab::APP_DIRS_PATTERN.match?(line) }