Fix setPatternColor on tropical fish bucket meta

Prior to this commit, the tropical fish bucket meta would set the body
color to the previous metas pattern colour when updating the pattern
colour.

This commit hence simply fixes this by using the proper body colour
value when updating the pattern color.

paper-server/src/main/java/org/bukkit/craftbukkit/inventory/CraftMetaTropicalFishBucket.java

@@ -128,7 +128,7 @@ class CraftMetaTropicalFishBucket extends CraftMetaItem implements TropicalFishB
         if (this.variant == null) {
             this.variant = 0;
         }
-        this.variant = CraftTropicalFish.getData(color, this.getPatternColor(), this.getPattern());
+        this.variant = CraftTropicalFish.getData(color, this.getBodyColor(), this.getPattern()); // Paper - properly set tropical fish pattern color without mutating body color
     }
 
     @Override