Add missing test source file to the build

Change-Id: I020ff281eaa49794aeb1853711485bc8c7047dd8
Signed-off-by: David Ostrovsky <david@ostrovsky.org>
diff --git a/org.eclipse.jgit.test/BUILD b/org.eclipse.jgit.test/BUILD
index 3c4c61b..b04ac55 100644
--- a/org.eclipse.jgit.test/BUILD
+++ b/org.eclipse.jgit.test/BUILD
@@ -20,6 +20,7 @@
     "nls/MissingPropertyBundle.java",
     "nls/NoPropertiesBundle.java",
     "nls/NonTranslatedBundle.java",
+    "revwalk/ObjectReachabilityTestCase.java",
     "revwalk/ReachabilityCheckerTestCase.java",
     "revwalk/RevQueueTestCase.java",
     "revwalk/RevWalkTestCase.java",