IndexDiffWithSymlinkTest: handle InaccessibleObjectException

On Java 16 this test throws InaccessibleObjectException, handle and
ignore it similar to IllegalAccessException.

Change-Id: I19b4f577579694a146516861a7ec567141f3464b

org.eclipse.jgit.test/tst/org/eclipse/jgit/indexdiff/IndexDiffWithSymlinkTest.java

diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/indexdiff/IndexDiffWithSymlinkTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/indexdiff/IndexDiffWithSymlinkTest.java
index 7e513d2..d02bfcd 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/indexdiff/IndexDiffWithSymlinkTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/indexdiff/IndexDiffWithSymlinkTest.java
@@ -59,6 +59,7 @@
 import java.io.OutputStream;
 import java.io.OutputStreamWriter;
 import java.io.Writer;
+import java.lang.reflect.InaccessibleObjectException;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
 import java.nio.file.Files;
@@ -227,7 +228,8 @@ public void testSymlinkWithEncodingDifference() throws Exception {
 				return (byte[]) method.invoke(p);
 			}
 		} catch (NoSuchMethodException | IllegalAccessException
-				| IllegalArgumentException | InvocationTargetException e) {
+				| IllegalArgumentException | InvocationTargetException
+				| InaccessibleObjectException e) {
 			// Ignore and fall through.
 		}
 		return null;