Remove an unused File reference in test code

Change-Id: Ib0d6c36811df719a53c66e9fa7460b89b2faf98b
Signed-off-by: Robin Rosenberg <robin.rosenberg@dewire.com>

org.eclipse.jgit.test/tst/org/eclipse/jgit/ignore/IgnoreCacheTest.java

@@ -131,7 +131,6 @@ public class IgnoreCacheTest extends RepositoryTestCase {
 		else
 			fail("Base directory not initialized");
 
-		test = new File("/tmp/not/part/of/repo/path");
 	}
 
 	public void testRules() {