message: fix town material probability mutation
diff: @@ -76,14 +76,22 @@ function getPriceModifier (): number {
  export function generateBuildingMaterial (town: Town, mainMaterial: MaterialTypes, buildingWealth: number): MaterialType {
  // Set probability for other buildings depending on the building 'tier'
  const buildingTier = getBuildingTier(town.roll.wealth, buildingWealth)
  +
  for (const material of keys(town.materialProbability)) {
  - if (town.materialProbability[material].tier.indexOf(buildingTier) !== -1) {
  - town.materialProbability[material].probability = 5
  + if (town.materialProbability[material].tier.includes(buildingTier)) {
  + town.materialProbability[material] = {
  + ...town.materialProbability[material],
  + probability: 5
  + }
  }
  }
  - town.materialProbability[mainMaterial].probability = 80
  - const tempMaterial = lib.weightedRandomFetcher(town, town.materialProbability, undefined, undefined, 'object') as MaterialType
  - return tempMaterial
  +
  + town.materialProbability[mainMaterial] = {
  + ...town.materialProbability[mainMaterial],
  + probability: 80
  + }
  +
  + return lib.weightedRandomFetcher(town, town.materialProbability, undefined, undefined, 'object') as MaterialType
  }
  export function getBuildingTier (townWealth: number, buildingWealth: number): number {
  