Don't check any revocation info on proxy certificates

Because proxy certificates typically come without any CRL information,
trying to check revocation on them will fail.  Better not to try
checking such information for them at all.

Reviewed-by: Rich Salz <rsalz@openssl.org>

crypto/x509/x509_vfy.c

diff --git a/crypto/x509/x509_vfy.c b/crypto/x509/x509_vfy.c
index 099a4d8..2874574 100644
--- a/crypto/x509/x509_vfy.c
+++ b/crypto/x509/x509_vfy.c
@@ -844,6 +844,9 @@
     ctx->current_crl_score = 0;
     ctx->current_reasons = 0;
 
+    if (x->ex_flags & EXFLAG_PROXY)
+        return 1;
+
     while (ctx->current_reasons != CRLDP_ALL_REASONS) {
         unsigned int last_reasons = ctx->current_reasons;