GOCBC-177: Do not panic due to unassigned pipeline consumer.
GOCBC-177: Do not panic due to unassigned pipeline consumer.

Change-Id: I1544337ff707d1c2ebc5637fca09a555f97894f1
Reviewed-on: http://review.couchbase.org/75701
Reviewed-by: Brett Lawson <c8c4369773d7d7226e031f0c4af62e3f38a08510@gmail.com>
Tested-by: Brett Lawson <c8c4369773d7d7226e031f0c4af62e3f38a08510@gmail.com>

brett19/gocbcore