bp: Fix PersistedClusterStateServiceTests.testSlowLogging

[mfussenegger]

Summary of the changes / Why this improves CrateDB

elastic/elasticsearch@34fc52d

Failed with:

java.lang.AssertionError: max must be >= min: 1, 0
	at __randomizedtesting.SeedInfo.seed([A4C1A6C6699E9943:17EC0019C06CE531]:0)
	at com.carrotsearch.randomizedtesting.generators.RandomNumbers.randomLongBetween(RandomNumbers.java:29)
	at org.elasticsearch.test.ESTestCase.randomLongBetween(ESTestCase.java:506)
	at org.elasticsearch.gateway.PersistedClusterStateServiceTests.testSlowLogging(PersistedClusterStateServiceTests.java:840)

Checklist

• Added an entry in CHANGES.txt for user facing changes
• Updated documentation & sql_features table for user facing changes
• Touched code is covered by tests
• CLA is signed
• This does not contain breaking changes, or if it does:
  • It is released within a major release
  • It is recorded in CHANGES.txt
  • It was marked as deprecated in an earlier release if possible
  • You've thought about the consequences and other components are adapted
    (E.g. AdminUI)

[matriv]

LGTM, thx!