Fix proc-macro-nested/METADATA

Bug: 166324735
Test: make
Change-Id: I120c8d6862c7ea4738491fc35d358da2cfb46e69
diff --git a/METADATA b/METADATA
index a328cee..67d5c26 100644
--- a/METADATA
+++ b/METADATA
@@ -6,8 +6,8 @@
     value: "https://crates.io/crates/proc-macro-nested"
   }
   url {
-    type: GIT
-    value: "https://github.com/dtolnay/proc-macro-hack"
+    type: ARCHIVE
+    value: "https://static.crates.io/crates/proc-macro-nested/proc-macro-nested-0.1.6.crate"
   }
   version: "0.1.6"
   license_type: NOTICE