MINOR: fix failing Streams system tests

[mjsax]

In #5850 the output that prints the current Kafka version was reformatted (space before : was removed):

Old format:

Kafka version : 2.2.0-SNAPSHOT

New format:

Kafka version: 2.2.0-SNAPSHOT

This breaks some Streams system tests that grep the logs for this line.

[mjsax]

Triggered system test: https://jenkins.confluent.io/job/system-test-kafka-branch-builder/2086/

Call for review @guozhangwang @bbejeck @vvcephei

[mjsax]

StreamsBrokerBounceTest system test failed -- seems to be unrelated to this fix though. All StreamsUpgradeTest passed. Are you ok if I merge this and we tackle the failing test separately?

Also EosIntegrationTest.shouldNotViolateEosIfOneTaskFailsWithState failed:

java.lang.AssertionError: 
Expected: <[KeyValue(0, 0), KeyValue(0, 1), KeyValue(0, 3), KeyValue(0, 6), KeyValue(0, 10), KeyValue(0, 15), KeyValue(0, 21), KeyValue(0, 28), KeyValue(0, 36), KeyValue(0, 45)]>
     but: was <[KeyValue(0, 0), KeyValue(0, 1), KeyValue(0, 3), KeyValue(0, 6), KeyValue(0, 10), KeyValue(0, 15), KeyValue(0, 21), KeyValue(0, 28), KeyValue(0, 36), KeyValue(0, 45), KeyValue(0, 55), KeyValue(0, 66), KeyValue(0, 78), KeyValue(0, 91), KeyValue(0, 105)]>
	at org.hamcrest.MatcherAssert.assertThat(MatcherAssert.java:20)
	at org.hamcrest.MatcherAssert.assertThat(MatcherAssert.java:8)
	at org.apache.kafka.streams.integration.EosIntegrationTest.checkResultPerKey(EosIntegrationTest.java:218)
	at org.apache.kafka.streams.integration.EosIntegrationTest.shouldNotViolateEosIfOneTaskFailsWithState(EosIntegrationTest.java:438)

Have seen this once in a while lately -- we should investigate.

Other Jenkins test failures seems to be unrelated.

Retest this please.

[bbejeck]

StreamsBrokerBounceTest system test failed -- seems to be unrelated to this fix though. All StreamsUpgradeTest passed. Are you ok if I merge this and we tackle the failing test separately?

Fine with me

[vvcephei]

Thanks!

[bbejeck]

@mjsax as side note this PR will help me as I'm working on another system test for broker upgrades and experienced the same failures

[mjsax]

@bbejeck Merge to trunk. You can rebase your PR to pick up the fix.

[bbejeck]

Thanks @mjsax!