Fix "instance variable @same_site not initialized" warnings
Fix "instance variable @same_site not initialized" warnings

Ref https://github.com/rack/rack/pull/1587.

iainbeeston/rails,georgeclaghorn/rails,betesh/rails,schuetzm/rails,eileencodes/rails,bogdanvlviv/rails,vipulnsward/rails,palkan/rails,kddeisz/rails,palkan/rails,MSP-Greg/rails,fabianoleittes/rails,fabianoleittes/rails,betesh/rails,prathamesh-sonpatki/rails,Stellenticket/rails,tgxworld/rails,tjschuck/rails,Envek/rails,yhirano55/rails,rafaelfranca/omg-rails,yhirano55/rails,eileencodes/rails,MSP-Greg/rails,lcreid/rails,starknx/rails,eileencodes/rails,eileencodes/rails,fabianoleittes/rails,joonyou/rails,kddeisz/rails,kmcphillips/rails,rails/rails,Vasfed/rails,mechanicles/rails,bogdanvlviv/rails,bogdanvlviv/rails,MSP-Greg/rails,kddeisz/rails,lcreid/rails,yawboakye/rails,fabianoleittes/rails,MSP-Greg/rails,repinel/rails,Edouard-chin/rails,yhirano55/rails,Stellenticket/rails,georgeclaghorn/rails,tgxworld/rails,rafaelfranca/omg-rails,Erol/rails,vipulnsward/rails,BlakeWilliams/rails,yahonda/rails,rails/rails,Erol/rails,gauravtiwari/rails,joonyou/rails,iainbeeston/rails,repinel/rails,tgxworld/rails,mechanicles/rails,tjschuck/rails,gauravtiwari/rails,Envek/rails,Envek/rails,rafaelfranca/omg-rails,esparta/rails,esparta/rails,jeremy/rails,jeremy/rails,EmmaB/rails-1,yhirano55/rails,Edouard-chin/rails,vipulnsward/rails,iainbeeston/rails,bogdanvlviv/rails,yahonda/rails,BlakeWilliams/rails,schuetzm/rails,Erol/rails,palkan/rails,yawboakye/rails,yalab/rails,Edouard-chin/rails,betesh/rails,repinel/rails,schuetzm/rails,kmcphillips/rails,gauravtiwari/rails,joonyou/rails,Vasfed/rails,tjschuck/rails,kmcphillips/rails,EmmaB/rails-1,prathamesh-sonpatki/rails,starknx/rails,tgxworld/rails,vipulnsward/rails,prathamesh-sonpatki/rails,joonyou/rails,lcreid/rails,yawboakye/rails,yawboakye/rails,tjschuck/rails,BlakeWilliams/rails,iainbeeston/rails,Stellenticket/rails,prathamesh-sonpatki/rails,Erol/rails,yalab/rails,georgeclaghorn/rails,yalab/rails,palkan/rails,lcreid/rails,mechanicles/rails,EmmaB/rails-1,Envek/rails,starknx/rails,yalab/rails,kddeisz/rails,BlakeWilliams/rails,rails/rails,schuetzm/rails,kmcphillips/rails,mechanicles/rails,betesh/rails,esparta/rails,jeremy/rails,Stellenticket/rails,Edouard-chin/rails,georgeclaghorn/rails,esparta/rails,jeremy/rails,yahonda/rails,rails/rails,Vasfed/rails,yahonda/rails,repinel/rails,Vasfed/rails