don't crash if min and max meseta is the same

src/ship/drops/mod.rs

@@ -131,7 +131,7 @@ impl<R: Rng + SeedableRng> DropTable<R> {
     }
 
     fn generate_meseta(&mut self, monster: &MonsterDropStats) -> Option<ItemDropType> {
-        Some(ItemDropType::Meseta(self.rng.gen_range(monster.min_meseta, monster.max_meseta)))
+        Some(ItemDropType::Meseta(self.rng.gen_range(monster.min_meseta, monster.max_meseta + 1)))
     }
 
     fn generate_typed_drop(&mut self, map_area: &MapArea, monster: &MonsterDropStats) -> Option<ItemDropType> {