SPIGOT-4874: Use empty loot context

Appears to work irrespective of what the loot table requires

src/main/java/org/bukkit/craftbukkit/CraftLootTable.java

@@ -90,7 +90,7 @@ public class CraftLootTable implements org.bukkit.loot.LootTable {
             builder.set(LootContextParameters.DAMAGE_SOURCE, DamageSource.playerAttack(nmsKiller));
         }
 
-        return builder.build(LootContextParameterSets.GENERIC);
+        return builder.build(LootContextParameterSets.EMPTY);
     }
 
     @Override