SPIGOT-4135: Fix DOLPHINS_GRACE PotionEffectType Wrapper.

By: md_5 <git@md-5.net>

paper-server/src/main/java/org/bukkit/craftbukkit/potion/CraftPotionEffectType.java

@@ -83,6 +83,8 @@ public class CraftPotionEffectType extends PotionEffectType {
             return "SLOW_FALLING";
         case 29:
             return "CONDUIT_POWER";
+        case 30:
+            return "DOLPHINS_GRACE";
         default:
             return "UNKNOWN_EFFECT_TYPE_" + getId();
         }