DiscoveryNetworkTest intermittently fails

[Nashatyrev]

Description

The DiscoveryNetworkTest .test() fails in ~25% of cases on Mac OS with the following exception:

org.opentest4j.AssertionFailedError: expected: <false> but was: <true>
    at org.junit.jupiter.api.AssertionUtils.fail(AssertionUtils.java:55)
    at org.junit.jupiter.api.AssertFalse.assertFalse(AssertFalse.java:40)
    at org.junit.jupiter.api.AssertFalse.assertFalse(AssertFalse.java:35)
    at org.junit.jupiter.api.Assertions.assertFalse(Assertions.java:210)
    at org.ethereum.beacon.discovery.DiscoveryNetworkTest.test(DiscoveryNetworkTest.java:151)

Frequency: 25%

Versions

• Software version: 5bb7c5a
• Java version: java 11.0.8 2020-07-14 LTS
  Java(TM) SE Runtime Environment 18.9 (build 11.0.8+10-LTS)
  Java HotSpot(TM) 64-Bit Server VM 18.9 (build 11.0.8+10-LTS, mixed mode)
• OS Name & Version: Mac OS Catalina 10.15.5