Don't use compression API for GnuTLS >= 3.6.0
GnuTLS removed compression completely.
--- a/loudmouth/lm-ssl-gnutls.c Sat May 04 16:03:51 2019 +0000
+++ b/loudmouth/lm-ssl-gnutls.c Sat May 04 18:24:41 2019 +0200
@@ -313,9 +313,11 @@
gnutls_cipher_suite_get_name(gnutls_kx_get(ssl->gnutls_session),
gnutls_cipher_get(ssl->gnutls_session),
gnutls_mac_get(ssl->gnutls_session)));
+#if GNUTLS_VERSION_NUMBER < 0x030600
lm_verbose ("GNUTLS negotiated compression: %s",
gnutls_compression_get_name (gnutls_compression_get
(ssl->gnutls_session)));
+#endif
ssl->started = TRUE;