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://maven.apache.org/maven-v4_0_0.xsd with 1 occurrences migrated to:
  https://maven.apache.org/maven-v4_0_0.xsd ([https](https://maven.apache.org/maven-v4_0_0.xsd) result 301).

# Ignored
These URLs were intentionally ignored.

* http://maven.apache.org/POM/4.0.0 with 2 occurrences
* http://www.w3.org/2001/XMLSchema-instance with 1 occurrences

Author: spring-operator

Diff for: pom.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/maven-v4_0_0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 	<groupId>org.springframework.samples</groupId>
 	<artifactId>spring-mvc-showcase</artifactId>