[5.15.0] Expectation is listed in 'active expectation' list after 'timeToLive' is expired

[mihalichzh]

MockServer version: 5.15.0

Describe the bug
Expectation is listed in 'active expectation list' after 'timeToLive' is expired.

To Reproduce
Steps to reproduce the behavior:

1. Set expectation with 'timeToLive' property defined, e.g.:

curl -X PUT 'localhost:1080/mockserver/expectation' \
-d '{
  "httpRequest": {
    "method": "GET",
    "path": "/2345",
  },
  "httpResponse": {
    "body": "This is an example of mocked response"
  },
  "timeToLive" : {
    "timeUnit" : "SECONDS",
    "timeToLive" : 30,
    "unlimited" : false
  }
}'

3. Wait for a 'timeToLive' to expire;
4. Check active expectations list.

Expected behavior
Expectation is removed after 'timeToLive' is expired.

Actual behavior
Expectation is not removed from active expectations list after 'timeToLive' is expired. Expectation is removed only after user performed request to MockServer (both matching/non-matching).