m_ssl_gnutls Fix build with GnuTLS 1.x

Fixes #409 reported by @SaberUK
Use a better server name in m_httpd.
Use the preprocessor to detect whether hash_map is available.
Merge pull request #413 from SaberUK/insp20+httpd

[2.0] Use a better server name in m_httpd.
Merge pull request #414 from SaberUK/insp20+hashmap

[2.0] Use the preprocessor to detect whether hash_map is available.