LongObjectIdTest: Remove self comparison test

This fixes test flagged by error prone:

LongObjectIdTest.java:294: error: [SelfComparison] An object is
compared to itself

		assertEquals(0, id1.compareTo(id1));

Change-Id: Ife339c92b9570db2471a2fc029b3bfa114044790
Signed-off-by: David Ostrovsky <david@ostrovsky.org>

org.eclipse.jgit.lfs.test/tst/org/eclipse/jgit/lfs/lib/LongObjectIdTest.java

@@ -291,7 +291,6 @@ public class LongObjectIdTest {
 				"0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef");
 		assertEquals(0, id1.compareTo(LongObjectId.fromString(
 				"0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef")));
-		assertEquals(0, id1.compareTo(id1));
 
 		assertEquals(-1, id1.compareTo(LongObjectId.fromString(
 				"1123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef")));