internal/database: skip .zip files in validation

When validating legacy database, ignore .zip files. (This is needed
now that we are publishing the full database as a zip file).

Change-Id: I426b25e3c6fb0252abe2d16e9259abae95f3063a
Reviewed-on: https://go-review.googlesource.com/c/vulndb/+/557816
Reviewed-by: Zvonimir Pavlinovic <zpavlinovic@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Tatiana Bradley <tatianabradley@google.com>
diff --git a/internal/database/legacydb/load.go b/internal/database/legacydb/load.go
index 51e1820..0134f3d 100644
--- a/internal/database/legacydb/load.go
+++ b/internal/database/legacydb/load.go
@@ -88,7 +88,7 @@
 		case f.IsDir():
 			return nil
 		// Skip files in the v1 spec.
-		case ext == ".gz" || dbv1.IsIndexEndpoint(fname):
+		case ext == ".gz" || ext == ".zip" || dbv1.IsIndexEndpoint(fname):
 			return nil
 		// In the top-level directory, web files and index files are OK.
 		case dir == dbPath && isIndexOrWebFile(fname, ext):