Update to the latest package_config

Change-Id: I9b6e9188393a3eb8505f8f4f322b5364dba501c9
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/209440
Reviewed-by: Jake Macdonald <[email protected]>
Commit-Queue: Nate Bosch <[email protected]>

Author: natebosch

DEPS

@@ -133,7 +133,7 @@ vars = {
   "mime_rev": "c931f4bed87221beaece356494b43731445ce7b8",
   "mockito_rev": "d39ac507483b9891165e422ec98d9fb480037c8b",
   "oauth2_rev": "7cd3284049fe5badbec9f2bea2afc41d14c01057",
-  "package_config_rev": "a84c0d45401f215fbe9384df923a38f4022a3c45",
+  "package_config_rev": "fb736aa12316dd2d882b202a438a6946a4b4bea0",
   "path_rev": "c20d73c3516d3a0061c90f14b761ff532b9bf707",
   "pedantic_rev": "66f2f6c27581c7936482e83be80b27be2719901c",
   "platform_rev": "c20e6fa315e9f8820e51c0ae721f63aff33b8e17",