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).

# 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://cloud.spring.io/ with 1 occurrences migrated to:
  https://cloud.spring.io/ ([https](https://cloud.spring.io/) result 200).
* http://maven.apache.org/xsd/assembly-1.1.2.xsd with 1 occurrences migrated to:
  https://maven.apache.org/xsd/assembly-1.1.2.xsd ([https](https://maven.apache.org/xsd/assembly-1.1.2.xsd) result 200).
* http://maven.apache.org/xsd/maven-4.0.0.xsd with 28 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).

# Ignored
These URLs were intentionally ignored.

* http://maven.apache.org/POM/4.0.0 with 56 occurrences
* http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.2 with 2 occurrences
* http://www.w3.org/2001/XMLSchema-instance with 29 occurrences

spring-cloud-function-samples/function-sample-aws-custom/src/assembly/zip.xml

@@ -1,6 +1,6 @@
 <assembly xmlns="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.2"
 	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-	xsi:schemaLocation="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.2 http://maven.apache.org/xsd/assembly-1.1.2.xsd">
+	xsi:schemaLocation="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.2 https://maven.apache.org/xsd/assembly-1.1.2.xsd">
 	<id>zip</id>
 	<formats>
 		<format>zip</format>