URL Cleanup

This commit updates URLs to prefer the https protocol. Redirects are not followed to avoid accidentally expanding intentionally shortened URLs (i.e. if using a URL shortener).

# HTTP URLs that Could Not Be Fixed
These URLs were unable to be fixed. Please review them to see if they can be manually resolved.

* http://xslthl.sf.net (301) with 1 occurrences could not be migrated:
   ([https](https://xslthl.sf.net) result AnnotatedConnectException).

# Fixed URLs

## Fixed Success
These URLs were switched to an https URL with a 2xx status. While the status was successful, your review is still recommended.

* http://asciidoctor.org with 1 occurrences migrated to:
  https://asciidoctor.org ([https](https://asciidoctor.org) result 200).
* http://maven.apache.org/xsd/maven-4.0.0.xsd with 18 occurrences migrated to:
  https://maven.apache.org/xsd/maven-4.0.0.xsd ([https](https://maven.apache.org/xsd/maven-4.0.0.xsd) result 200).
* http://sourceforge.net/projects/xslthl/ with 14 occurrences migrated to:
  https://sourceforge.net/projects/xslthl/ ([https](https://sourceforge.net/projects/xslthl/) result 200).
* http://www.w3.org/TR/CSS21/propidx.html with 1 occurrences migrated to:
  https://www.w3.org/TR/CSS21/propidx.html ([https](https://www.w3.org/TR/CSS21/propidx.html) result 200).

# Ignored
These URLs were intentionally ignored.

* http://maven.apache.org/POM/4.0.0 with 36 occurrences
* http://www.w3.org/2001/XMLSchema-instance with 18 occurrences

spring-cloud-task-samples/taskprocessor/pom.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 		 xmlns="http://maven.apache.org/POM/4.0.0"
-		 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+		 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 
 	<groupId>io.spring.cloud</groupId>