Expose getObjectToTransfer method of FileLfsServlet

Providing own implementation to doGet/doPut methods is troublesome when
this method is private.

Change-Id: I098cdc5cb90410eaaebc56c88c2d9e168584dd6d
Signed-off-by: Jacek Centkowski <geminica.programs@gmail.com>
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

org.eclipse.jgit.lfs.server/src/org/eclipse/jgit/lfs/server/fs/FileLfsServlet.java

@@ -125,7 +125,20 @@ public class FileLfsServlet extends HttpServlet {
 		}
 	}
 
-	private AnyLongObjectId getObjectToTransfer(HttpServletRequest req,
+	/**
+	 * Retrieve object id from request
+	 *
+	 * @param req
+	 *            servlet request
+	 * @param rsp
+	 *            servlet response
+	 * @return object id, or <code>null</code> if the object id could not be
+	 *         retrieved
+	 * @throws IOException
+	 *             if an I/O error occurs
+         * @since 4.6
+	 */
+	protected AnyLongObjectId getObjectToTransfer(HttpServletRequest req,
 			HttpServletResponse rsp) throws IOException {
 		String info = req.getPathInfo();
 		int length = 1 + Constants.LONG_OBJECT_ID_STRING_LENGTH;