Backport of part of OF-1353 to facilitate OF-1020.

This implementation is a backport from master to the 4.1 branch, of an API change that was part of OF-1353. OF-1020 needs this API. This specific implementation should not live outside of the 4.1 branch.

src/java/org/jivesoftware/openfire/update/AvailablePlugin.java

@@ -20,6 +20,9 @@
 
 package org.jivesoftware.openfire.update;
 
+import java.net.MalformedURLException;
+import java.net.URL;
+
 /**
  * Plugin available at igniterealtime.org. The plugin may or may not be locally installed.
  *
@@ -200,6 +203,24 @@ public class AvailablePlugin {
         return Long.parseLong(fileSize);
     }
 
+    /**
+     * URL from where the latest version of the plugin can be downloaded.
+     *
+     * @return download URL.
+     */
+    // This implementation is a backport from master to the 4.1 branch, of an API change that was part of OF-1353.
+    // OF-1020 needs this API. This specific implementation should not live outside of the 4.1 branch.
+    public URL getDownloadURL() {
+        try
+        {
+            return new URL( url );
+        }
+        catch ( MalformedURLException e )
+        {
+            return null;
+        }
+    }
+
     /**
      * Returns the hash code for this object.
      * @return the hash code.