MB-11697 Use finite timeout for pre-collection HEAD request.

Change-Id: I79bb78888396e5725f4731dd6438559fff15e50b
Reviewed-on: http://review.couchbase.org/39357
Tested-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>