Remove mbedtls_ssl_conf_sig_hashes from comments

Signed-off-by: Ben Taylor <ben.taylor@linaro.org>

programs/fuzz/fuzz_client.c

@@ -137,7 +137,7 @@ int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size)
     }
 #endif
     //There may be other options to add :
-    // mbedtls_ssl_conf_cert_profile, mbedtls_ssl_conf_sig_hashes
+    // mbedtls_ssl_conf_cert_profile
 
     if (mbedtls_ssl_setup(&ssl, &conf) != 0) {
         goto exit;