Fix MSVC warning
We know the length of the ALPN string is always less than 255, so the cast to
uint8_t is safe.
@@ -11553,7 +11553,7 @@ int mbedtls_ssl_context_save( mbedtls_ssl_context *ssl,
#if defined(MBEDTLS_SSL_ALPN)
{
const uint8_t alpn_len = ssl->alpn_chosen
- ? strlen( ssl->alpn_chosen )
+ ? (uint8_t) strlen( ssl->alpn_chosen )
: 0;
used += 1 + alpn_len;
