Clean-up an unused method.

git-svn-id: https://svn.apache.org/repos/asf/felix/trunk@576135 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/framework/src/main/java/org/apache/felix/framework/SystemBundleArchive.java b/framework/src/main/java/org/apache/felix/framework/SystemBundleArchive.java
index 2452fce..70911e7 100644
--- a/framework/src/main/java/org/apache/felix/framework/SystemBundleArchive.java
+++ b/framework/src/main/java/org/apache/felix/framework/SystemBundleArchive.java
@@ -21,7 +21,6 @@
 import org.apache.felix.framework.cache.*;
 import java.io.File;
 import java.io.InputStream;
-import java.security.cert.X509Certificate;
 import java.util.Map;
 
 import org.apache.felix.framework.util.FelixConstants;
@@ -75,11 +74,6 @@
                 public void dispose() throws Exception
                 {
                 }
-
-                protected X509Certificate[] getRevisionCertificates()
-                {
-                    return null;
-                }
             };
         }
         catch (Exception ex)