message: Remove river yield change for Lumbermill
diff: <iYieldChange>0</iYieldChange>
  <iYieldChange>1</iYieldChange>
  </YieldChanges>
  - <RiverSideYieldChange>
  - <iYield>0</iYield>
  - <iYield>1</iYield>
  - <iYield>0</iYield>
  - </RiverSideYieldChange>
  <bActsAsCity>0</bActsAsCity>
  <bHillsMakesValid>0</bHillsMakesValid>
  <bFreshWaterMakesValid>0</bFreshWaterMakesValid>
  