Fix comments about X.509 versions
diff --git a/include/polarssl/x509_crt.h b/include/polarssl/x509_crt.h
index e90e357..4bf8e56 100644
--- a/include/polarssl/x509_crt.h
+++ b/include/polarssl/x509_crt.h
@@ -59,7 +59,7 @@
     x509_buf raw;               /**< The raw certificate data (DER). */
     x509_buf tbs;               /**< The raw certificate body (DER). The part that is To Be Signed. */
 
-    int version;                /**< The X.509 version. (0=v1, 1=v2, 2=v3) */
+    int version;                /**< The X.509 version. (1=v1, 2=v2, 3=v3) */
     x509_buf serial;            /**< Unique id for certificate issued by a specific CA. */
     x509_buf sig_oid1;          /**< Signature algorithm, e.g. sha1RSA */