Avoid trailing dots in SNI hostnames
Avoid trailing dots in SNI hostnames

Sending the trailing dot violates RFC 6066 section 3: "The hostname is
represented as a byte string using ASCII encoding without a trailing
dot." gnutls_server_name_set() should probably strip the trailing dot
for us, but man page says we are responsible for doing so manually... so
do it.

Hopefully fixes #11

GNOME/glib-networking,GNOME/glib-networking,GNOME/glib-networking