Fix rare case where ruins would delete an AI unit while trying to upgrade it (#7084)

* Fix rare case where ruins could delete AI units when upgrading the unit

* Don't moveToTile if the unit is destroyed

* Update comment

* Forgot to uncomment line

* Move currentMovement = 0f to destroy()

core/src/com/unciv/logic/map/MapUnit.kt

@@ -924,6 +924,7 @@ class MapUnit {
     fun destroy() {
         val currentPosition = Vector2(getTile().position)
         civInfo.attacksSinceTurnStart.addAll(attacksSinceTurnStart.asSequence().map { CivilizationInfo.HistoricalAttackMemory(this.name, currentPosition, it) })
+        currentMovement = 0f
         removeFromTile()
         civInfo.removeUnit(this)
         civInfo.updateViewableTiles()

core/src/com/unciv/logic/map/TileInfo.kt

@@ -1104,7 +1104,7 @@ open class TileInfo {
         when {
             airUnits.contains(mapUnit) -> airUnits.remove(mapUnit)
             civilianUnit == mapUnit -> civilianUnit = null
-            else -> militaryUnit = null
+            militaryUnit == mapUnit -> militaryUnit = null
         }
     }
 

core/src/com/unciv/logic/map/UnitMovementAlgorithms.kt

@@ -417,7 +417,7 @@ class UnitMovementAlgorithms(val unit: MapUnit) {
     }
 
     fun moveToTile(destination: TileInfo, considerZoneOfControl: Boolean = true) {
-        if (destination == unit.getTile()) return // already here!
+        if (destination == unit.getTile() || unit.isDestroyed) return // already here (or dead)!
 
 
         if (unit.baseUnit.movesLikeAirUnits()) { // air units move differently from all other units