SPIGOT-4106: Fish from buckets despawn

nms-patches/EntityFish.patch

@@ -0,0 +1,10 @@
+--- a/net/minecraft/server/EntityFish.java
++++ b/net/minecraft/server/EntityFish.java
+@@ -67,6 +67,7 @@
+ 
+     public void s(boolean flag) {
+         this.datawatcher.set(EntityFish.b, Boolean.valueOf(flag));
++        this.persistent = !this.isTypeNotPersistent(); // CraftBukkit - SPIGOT-4106 update persistence
+     }
+ 
+     public void b(NBTTagCompound nbttagcompound) {