nist-pkits: update README.chromium metadata

Bug: chromium:365320414
Change-Id: I5d18425257dd87fe33a72dece194c2fe1977e51d
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/71067
Reviewed-by: David Benjamin <davidben@google.com>
Auto-Submit: Adam Langley <agl@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
diff --git a/pki/testdata/nist-pkits/README.chromium b/pki/testdata/nist-pkits/README.chromium
index a862062..3f09e09 100644
--- a/pki/testdata/nist-pkits/README.chromium
+++ b/pki/testdata/nist-pkits/README.chromium
@@ -2,9 +2,10 @@
 Short Name: NIST PKITS
 URL: http://csrc.nist.gov/groups/ST/crypto_apps_infra/pki/pkitesting.html
 Version: 1.0.1
-Date: April 14, 2011
+Date: 2011-04-14
 License: Public Domain: United States Government Work under 17 U.S.C. 105
 Shipped: no
+Security Critical: no
 
 Description:
 The Public Key Interoperability Test Suite (PKITS) is a comprehensive X.509