SPIGOT-6840: Fire resistance potion effect does not prevent melt damage of snow golem

By: Doc <nachito94@msn.com>

paper-server/src/main/java/org/bukkit/craftbukkit/util/CraftDamageSource.java

@@ -18,8 +18,8 @@ public final class CraftDamageSource extends DamageSource {
         }
 
         // Check fire
-        if (original.isExplosion()) {
-            newSource.setExplosion();
+        if (original.isFire()) {
+            newSource.setIsFire();
         }
 
         return newSource;