Fixing some bugs.
Include proper formatting for Enchantment try/catch
Stop accepting enchantment registrations after an enchantment is registered

This change allows the EnchantmentCommand to rebuild the newly added enchantments.
Unregister the enchantment if previously registered

When the server is reloaded the Enchantments are serialized and unserialized.  When it is unserialized it is unserialized as an Enchantment and therefore no longer an instance of CustomEnchantment and any custom listeners will not function.  If the enchantment is already registered then it will not be overwritten and will remain an Enchantment.  Unregistering ensures that the stored instance is an instance of CustomEnchantment.
Fixed line indents

Spaces -> Tabs
Merge pull request #4 from ELCHILEN0/master

Fix issue with the CustomEnchantment instance being lost on reload