Change VERSION_URL for 6.0 release

* Move to the /release/ directory, where releases will be posted
  * Switch back to HTTP until the issues with HTTPClient are resolved

subsonic-main/src/main/java/net/sourceforge/subsonic/service/VersionService.java

@@ -69,7 +69,7 @@ public class VersionService {
     /**
      * URL from which to fetch latest versions.
      */
-    private static final String VERSION_URL = "https://libresonic.org/backend/version.view";
+    private static final String VERSION_URL = "http://libresonic.org/release/version.txt";
 
     public void init() {
         ServiceLocator.setVersionService(this);