Fix type parameter in javadoc in TestRepository.delete(String ref)

Type parameter T extends AnyObjectId in signature of update(String, T)

Change-Id: I9c13ddc572b8e94d5c7854f4de1f8206cb5e99ca
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

org.eclipse.jgit.junit/src/org/eclipse/jgit/junit/TestRepository.java

@@ -591,7 +591,7 @@ public class TestRepository<R extends Repository> {
 	 *
 	 * @param ref
 	 *	      the name of the reference to delete. This is normalized
-	 *	      in the same way as {@link #update(String, T)}.
+	 *	      in the same way as {@link #update(String, AnyObjectId)}.
 	 * @throws Exception
 	 * @since 4.4
 	 */