esitag: Try to fix flaky TestEntities_QueryResources
esitag: Try to fix flaky TestEntities_QueryResources

More specific the "QueryResources Request context canceled" test might
not get cancelled once in a while. Very strange. So now we try to add
the sleep after the call to QueryResources in the hope that the
context cancellation has enough time to be processed.

corestoreio/caddy-esi,corestoreio/caddy-esi,SchumacherFM/caddyesi,corestoreio/caddy-esi,SchumacherFM/caddyesi,SchumacherFM/caddyesi