ssl_tls.c: Return in error if default config fails

Signed-off-by: Ronald Cron <ronald.cron@arm.com>
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 0e1d0ea..e144c24 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -4246,6 +4246,7 @@
                 conf->max_major_ver = 0;
                 conf->min_minor_ver = 0;
                 conf->max_minor_ver = 0;
+                return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE );
             }
 #endif
             else
@@ -4297,6 +4298,7 @@
                 conf->max_major_ver = 0;
                 conf->min_minor_ver = 0;
                 conf->max_minor_ver = 0;
+                return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE );
             }
 #endif
             else