Fixed repair enchant downgrade

Changelog.txt

@@ -12,6 +12,7 @@ Version 1.3.10-dev
  + Added ability for custom blocks to drop a range of items.
  + Added Ability API functions
  + Added 50% & 150% XP boost perks
+ = Fixed Repair enchant downgrade not working
  = Fixed NPE caused by Spout players after a /reload
  = Fixed ConcurrentModificationException on world unload
  = Fixed players never being removed from memory (memory leak)

src/main/java/com/gmail/nossr50/skills/repair/Repair.java

@@ -109,7 +109,7 @@ public class Repair {
 
                 if (configInstance.getArcaneForgingDowngradeEnabled() && enchantLevel > 1) {
                     if (random.nextInt(100) <= getDowngradeChance(rank)) {
-                        is.addEnchantment(enchantment, enchantLevel--);
+                        is.addEnchantment(enchantment, --enchantLevel);
                         downgraded = true;
                     }
                 }