Update-Queries with multiple tables do not work properly #11

I just ran into an issue with one of my queries and it seems sqlvet cannot handle this sort of Update-Query:

UPDATE activities u
	SET ref_id = c.ref_id
FROM activities c 
WHERE u.object_id = c.object_id 
	AND c.event_type = 'create'
	AND u.event_type = 'update'
	AND u.ref_id <= 0

The Error-Message is

ERROR: table `u` not available for query

Currently I just ignore this one query using the //sqlvet:ignore but it would be nice to have it fixed.