Squash warnings about failing to normalise NULL recipient
Squash warnings about failing to normalise NULL recipient

It's valid to send IQs with no recipient, so stanza_iq_handler_new()
will often be called with recipient == NULL. Previously, it would try to
normalize NULL, fail, emit a debug message, and fall back to using NULL;
this patch stops it trying to normalize NULL in the first place.

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

freedesktop-unofficial-mirror/wocky,noonien-d/wocky,freedesktop-unofficial-mirror/wocky,noonien-d/wocky,noonien-d/wocky,freedesktop-unofficial-mirror/wocky