Downgrade a QUIC_BUG to a warning.

The path that triggers QUIC_BUG can be triggered by user input, and thus it should not count as a bug.

PiperOrigin-RevId: 338673359
Change-Id: I26d32eca4a01dcfc5bf3f8055b9556093f7a0848
diff --git a/quic/core/crypto/certificate_view.cc b/quic/core/crypto/certificate_view.cc
index cc5aea7..2335769 100644
--- a/quic/core/crypto/certificate_view.cc
+++ b/quic/core/crypto/certificate_view.cc
@@ -106,7 +106,7 @@
 absl::optional<quic::QuicWallTime> ParseDerTime(unsigned tag,
                                                 absl::string_view payload) {
   if (tag != CBS_ASN1_GENERALIZEDTIME && tag != CBS_ASN1_UTCTIME) {
-    QUIC_BUG << "Invalid tag supplied for a DER timestamp";
+    QUIC_DLOG(WARNING) << "Invalid tag supplied for a DER timestamp";
     return absl::nullopt;
   }