PackExtBlockCacheTableTest: suppress unchecked conversion warnings

Change-Id: I5fcad7a824c4a320683d11da52c4e2035231f85d

org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/dfs/PackExtBlockCacheTableTest.java

diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/dfs/PackExtBlockCacheTableTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/dfs/PackExtBlockCacheTableTest.java
index 72abbf1..d904946 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/dfs/PackExtBlockCacheTableTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/dfs/PackExtBlockCacheTableTest.java
@@ -35,7 +35,7 @@
 import org.junit.Test;
 import org.mockito.Mockito;
 
-@SuppressWarnings("boxing")
+@SuppressWarnings({ "boxing", "unchecked" })
 public class PackExtBlockCacheTableTest {
 	@Test
 	public void fromBlockCacheConfigs_createsDfsPackExtBlockCacheTables() {