Fix links in documentations

- Fix broken links
- Use HTTPS where possible,
- Remove spring-security-oauth2-docs as it is no longer used
- Remove https://github.com/ThierrySquirrel/rocketmq-spring-boot-starter.
  This starter is 404 and https://github.com/rocketmq/rocketmq-spring-boot-starter
  hasn't been updated for 4 years.
- Clean up nohttp allowlist.lines.

See gh-31887

src/nohttp/allowlist.lines

@@ -1,9 +1,6 @@
-^http://exslt.org/common.*
 ^http://ganglia.sourceforge.net.*
-^http://hsqldb.org.*
 ^http://livereload.com/.*
-^http://logback.qos.ch/manual/loggingSeparation.html
 ^http://schemas.xmlsoap.org/.*
 ^http://www.jdotsoft.com.*
 ^http://www.liquibase.org/xml/ns/dbchangelog/.*
-^http://www.w3.org/2000/09/xmldsig.*
+^http://www.w3.org/2000/09/xmldsig.*