fixed Maven Central download URL

Author: stefan-zobel

docs/index.html

@@ -38,9 +38,9 @@ <h3 id="javadoc">Javadoc online</h3>
 <h3 id="files">Downloads</h3>
 
 <ul>
-  <li><a href="http://central.maven.org/maven2/net/sourceforge/streamsupport/java9-concurrent-backport/2.0.0/java9-concurrent-backport-2.0.0.jar">java9-concurrent-backport-2.0.0.jar</a> - Java 8 Jar file (Bytecode version 52)</li>
-  <li><a href="http://central.maven.org/maven2/net/sourceforge/streamsupport/java9-concurrent-backport/2.0.0/java9-concurrent-backport-2.0.0-javadoc.jar">java9-concurrent-backport-2.0.0-javadoc.jar</a> - Javadoc API documentation</li>
-  <li><a href="http://central.maven.org/maven2/net/sourceforge/streamsupport/java9-concurrent-backport/2.0.0/java9-concurrent-backport-2.0.0-sources.jar">java9-concurrent-backport-2.0.0-sources.jar</a> - Java source code</li>
+  <li><a href="https://repo.maven.apache.org/maven2/net/sourceforge/streamsupport/java9-concurrent-backport/2.0.0/java9-concurrent-backport-2.0.0.jar">java9-concurrent-backport-2.0.0.jar</a> - Java 8 Jar file (Bytecode version 52)</li>
+  <li><a href="https://repo.maven.apache.org/maven2/net/sourceforge/streamsupport/java9-concurrent-backport/2.0.0/java9-concurrent-backport-2.0.0-javadoc.jar">java9-concurrent-backport-2.0.0-javadoc.jar</a> - Javadoc API documentation</li>
+  <li><a href="https://repo.maven.apache.org/maven2/net/sourceforge/streamsupport/java9-concurrent-backport/2.0.0/java9-concurrent-backport-2.0.0-sources.jar">java9-concurrent-backport-2.0.0-sources.jar</a> - Java source code</li>
 </ul>