message: Reduce effect of flanking promotions
diff: <Description>TXT_KEY_PROMOTION_FLANKING2</Description>
  <Sound>AS2D_IF_LEVELUP</Sound>
  <PromotionPrereqOr1>PROMOTION_FLANKING1</PromotionPrereqOr1>
  - <iPlainsAttack>30</iPlainsAttack>
  + <iPlainsAttack>20</iPlainsAttack>
  <UnitCombats>
  <UnitCombat>
  <UnitCombatType>UNITCOMBAT_LIGHT_CAVALRY</UnitCombatType>
  <Sound>AS2D_IF_LEVELUP</Sound>
  <PromotionPrereqOr1>PROMOTION_FLANKING2</PromotionPrereqOr1>
  <iWithdrawalChange>25</iWithdrawalChange>
  - <iPlainsDefense>50</iPlainsDefense>
  + <iPlainsDefense>25</iPlainsDefense>
  <UnitCombats>
  <UnitCombat>
  <UnitCombatType>UNITCOMBAT_LIGHT_CAVALRY</UnitCombatType>
  