add comment for clarification

Author: stoty

zookeeper-server/src/main/java/org/apache/zookeeper/common/ClientX509Util.java

@@ -165,6 +165,8 @@ private SslContextBuilder handleTcnativeOcspStapling(SslContextBuilder builder,
             }
             builder.enableOcsp(true);
         } else if (tcnativeOcspStapling.isFalse()) {
+            // Disabling OCSP for the builder is always safe.
+            // This is the same as the builder default, effectively a noop.
             builder.enableOcsp(false);
         }
         return builder;