Summary:
The queue size stat is updated every time we pop from queue.
This means it won't get updated if we get requests while all threads are
busy processing some long running request. I don't think we care about
the exact queue size in that case, so that is fine.
Reviewers: mferencevic
Reviewed By: mferencevic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1213