Update NOTICE.txt - 'developed at' not 'developed by'

NOTICE.txt

diff --git a/NOTICE.txt b/NOTICE.txt
index 27ade1a..81c3c5d 100644
--- a/NOTICE.txt
+++ b/NOTICE.txt
@@ -1,5 +1,5 @@
 Apache Commons Proxy
 Copyright 2005-2023 The Apache Software Foundation
 
-This product includes software developed by
+This product includes software developed at
 The Apache Software Foundation (http://www.apache.org/).