change(esp-tls): make wolfSSL backend send SNI and enable OCSP

Almost all sites these days are virtually hosted and hence
SNI (server name indicator TLS extension) should be enabled by
default.

In addition this change enables OCSP (online server status protocol)
support for esp-tls clients using the wolfSSL backend.
The 3 code lines enable OCSP stabling v1.
By default this feature is disabled.
(I will send another PR on esp-wolfssl repository to allow to
enable it easily.)

components/esp-tls/esp_tls_wolfssl.c

@@ -310,6 +310,14 @@ static esp_err_t set_client_config(const char *hostname, size_t hostlen, esp_tls
 #endif /* CONFIG_WOLFSSL_HAVE_ALPN */
     }
 
+#ifdef CONFIG_WOLFSSL_HAVE_OCSP
+    wolfSSL_CTX_EnableOCSPStapling((WOLFSSL_CTX *)tls->priv_ctx );
+    wolfSSL_UseOCSPStapling((WOLFSSL *)tls->priv_ssl, WOLFSSL_CSR_OCSP, 0);
+    wolfSSL_CTX_EnableOCSP((WOLFSSL_CTX *)tls->priv_ctx, 0);
+#endif
+
+    wolfSSL_CTX_UseSNI(tls->priv_ctx, WOLFSSL_SNI_HOST_NAME, hostname, hostlen);
+
     wolfSSL_set_fd((WOLFSSL *)tls->priv_ssl, tls->sockfd);
     return ESP_OK;
 }