Remove Leftover Constants Dependancy y2017 constants

Change-Id: If1a722d6409cb3470ecbf6cc840eea6cb0ddbe8c
diff --git a/y2017/BUILD b/y2017/BUILD
index 8bf2ff8..96b2d92 100644
--- a/y2017/BUILD
+++ b/y2017/BUILD
@@ -11,7 +11,6 @@
     ],
     visibility = ["//visibility:public"],
     deps = [
-        "//aos:once",
         "//aos/logging",
         "//aos/mutex",
         "@com_google_absl//absl/base",