Remove unrooted_must_root annotation from unions (fixes #2661).

The unsafety was fixed as part of the SpiderMonkey upgrade; this removes the now unused annotation.
servo · bors-servo · Jul 29, 2015 · Jul 28, 2015 · Jul 28, 2015 · efa12e696371a7a15ba937d0fc256985de1bddaf
commit efa12e696371a7a15ba937d0fc256985de1bddaf
diff --git a/components/script/dom/bindings/codegen/CodegenRust.py b/components/script/dom/bindings/codegen/CodegenRust.py
@@ -3445,7 +3445,6 @@ def define(self):
         # XXXManishearth The following should be #[must_root],
         # however we currently allow it till #2661 is fixed
         return ("""\
-#[allow(unrooted_must_root)]
 pub enum %s {
 %s
 }