Adds a missing null check

src/main/java/net/knarcraft/blacksmith/util/ConfigHelper.java

@@ -19,6 +19,9 @@ public final class ConfigHelper {
      * @return <p>The value as a string list</p>
      */
     public static List<String> asStringList(Object value) {
+        if (value == null) {
+            return new ArrayList<>();
+        }
         if (value instanceof String) {
             return List.of(((String) value).split(","));
         } else {