Fix Checkstyle suppressions DTD link.
diff --git a/checkstyle-suppressions.xml b/checkstyle-suppressions.xml
index 2f36a9d..635ac17 100644
--- a/checkstyle-suppressions.xml
+++ b/checkstyle-suppressions.xml
@@ -1,6 +1,6 @@
 <?xml version="1.0"?>
 <!DOCTYPE suppressions PUBLIC
-        "-//Puppy Crawl//DTD Suppressions 1.0//EN"
+        "-//Checkstyle//DTD SuppressionFilter Configuration 1.0//EN"
         "https://checkstyle.org/dtds/suppressions_1_0.dtd">
 <!--
    Licensed to the Apache Software Foundation (ASF) under one or more