Use HTTPS instead of HTTP to resolve dependencies

This fixes a security vulnerability in this project where the `pom.xml`
files were configuring Maven to resolve dependencies over HTTP instead of
HTTPS.

Signed-off-by: Jonathan Leitschuh <Jonathan.Leitschuh@gmail.com>

pom.xml

@@ -153,14 +153,14 @@
 	<repositories>
 		<repository>
 			<id>repo.jenkins-ci.org</id>
-			<url>http://repo.jenkins-ci.org/public/</url>
+			<url>https://repo.jenkins-ci.org/public/</url>
 		</repository>
 	</repositories>
 
 	<pluginRepositories>
 		<pluginRepository>
 			<id>repo.jenkins-ci.org</id>
-			<url>http://repo.jenkins-ci.org/public/</url>
+			<url>https://repo.jenkins-ci.org/public/</url>
 		</pluginRepository>
 	</pluginRepositories>
 </project>