Fix C++ build issue when MBEDTLS_ASN1_PARSE_C is not enabled

Signed-off-by: Jan Bruckner <jan@janbruckner.de>
diff --git a/include/mbedtls/asn1.h b/include/mbedtls/asn1.h
index c7aae0f..a044543 100644
--- a/include/mbedtls/asn1.h
+++ b/include/mbedtls/asn1.h
@@ -644,10 +644,10 @@
 /** \} name Functions to parse ASN.1 data structures */
 /** \} addtogroup asn1_module */
 
+#endif /* MBEDTLS_ASN1_PARSE_C */
+
 #ifdef __cplusplus
 }
 #endif
 
-#endif /* MBEDTLS_ASN1_PARSE_C */
-
 #endif /* asn1.h */