Backport PR #908 on branch 1.x (Fix owasp link) (#909)

Co-authored-by: Steven Silvester <[email protected]>

docs/source/operators/public-server.rst

@@ -180,7 +180,7 @@ compliant self-signed certificate that will not raise warnings, it is possible
 certificate and follow the steps in :ref:`using-lets-encrypt` to set up a
 public server.
 
-.. _OWASP: https://www.owasp.org/index.php/Main_Page
+.. _OWASP: https://owasp.org/sitemap/
 .. _tutorial: https://arstechnica.com/information-technology/2009/12/how-to-get-set-with-a-secure-sertificate-for-free/
 
 .. _jupyter_public_server: