Re-enable test_merger_repack test

Fix typo with build_history.

Change-Id: Ia3d4bcd24396ab50632df14d63c696d4e071d931
Signed-off-by: Paul Belanger <pabelanger@redhat.com>
diff --git a/tests/test_scheduler.py b/tests/test_scheduler.py
index 1347638..789ab40 100755
--- a/tests/test_scheduler.py
+++ b/tests/test_scheduler.py
@@ -1540,7 +1540,6 @@
         self.assertEqual(self.countJobResults(self.history, 'ABORTED'), 15)
         self.assertEqual(len(self.history), 44)
 
-    @skip("Disabled for early v3 development")
     def test_merger_repack(self):
         "Test that the merger works after a repack"
 
@@ -1557,7 +1556,7 @@
         self.assertEqual(A.data['status'], 'MERGED')
         self.assertEqual(A.reported, 2)
         self.assertEmptyQueues()
-        self.worker.build_history = []
+        self.build_history = []
 
         path = os.path.join(self.git_root, "org/project")
         print(repack_repo(path))