ConnectionError: define server-message key.
ConnectionError: define server-message key.

Really? We didn't have a well-defined key for a human-readable message
from the server already? This was part of the point of this signal.

Reviewed-by: Sjoerd Simons <1371fd10dd05a897e5b55dc6ae4fbafa1f84c6ec@collabora.co.uk>

freedesktop-unofficial-mirror/telepathy__telepathy-spec,TelepathyIM/telepathy-spec