TEST: fix jgit target

Found by buck targets aborting if plugin is in tree.

Change-Id: If93890086608780df0b6bbcfd1b68e44ec440458
diff --git a/BUCK b/BUCK
index 17cda8a..1987215 100644
--- a/BUCK
+++ b/BUCK
@@ -7,7 +7,7 @@
     '//gerrit-common:server',
     '//gerrit-reviewdb:server',
     '//gerrit-server:server',
-    '//lib/jgit:jgit',
+    '//lib/jgit/org.eclipse.jgit:jgit',
     '//lib:guava',
     '//lib:gwtorm',
    ]