sample/https-client: replace ERR_remove_state() by ERR_remove_thread_…

…state()

Since ERR_remove_state() is deprecated:
  $ git log --grep ERR_remove_thread_state
  commit 2ecd2ededece66bf090fefc93ef3ddb672d9e71a
  Author: Bodo Möller <[email protected]>
  Date:   Wed Aug 13 19:30:01 2008 +0000

      Mention ERR_remove_state() deprecation, and ERR_remove_thread_state(NULL).

Link: https://www.openssl.org/docs/manmaster/crypto/ERR_remove_state.html

sample/https-client.c

@@ -471,7 +471,7 @@ main(int argc, char **argv)
 	EVP_cleanup();
 	ERR_free_strings();
 
-	ERR_remove_state(0);
+	ERR_remove_thread_state(NULL);
 	CRYPTO_cleanup_all_ex_data();
 
 	sk_SSL_COMP_free(SSL_COMP_get_compression_methods());