fix overshield

vacuum_gambit.p8

@@ -568,6 +568,7 @@ function ship_m:refresh_shield()
  if (lframe < self.shield_refresh_ready) return
  if (self.power < self.shieldcost) return
  self.shield += 1
+ self.shield = min(self.shield, self.maxshield)
  self.power -= self.shieldcost
  self.shield_refresh_ready = lframe + self.shieldcooldown
 end