Make handshake::min_minor_ver client only

Signed-off-by: Ronald Cron <ronald.cron@arm.com>
diff --git a/library/ssl_misc.h b/library/ssl_misc.h
index c187f0f..826dabd 100644
--- a/library/ssl_misc.h
+++ b/library/ssl_misc.h
@@ -539,8 +539,10 @@
     uint8_t resume;                     /*!<  session resume indicator*/
     uint8_t cli_exts;                   /*!< client extension presence*/
 
+#if defined(MBEDTLS_SSL_CLI_C)
     /*!< Minimum minor version to be negotiated. */
     unsigned char min_minor_ver;
+#endif
 
 #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
     uint8_t sni_authmode;               /*!< authmode from SNI callback     */