test(kafka): Bump the default poll timeout from 1 to 2s (#3465)

Should hopefully fix: #3169 - it fails when trying to get outcomes, it
does not specify a timeout and sometimes an outcome hasn't arrived yet.

This does slightly increase the time it takes for a failing test, but
shouldn't affect the duration of succeeding tests.

tests/integration/fixtures/processing.py

@@ -156,7 +156,7 @@ def __init__(self, consumer, options, topic_name, timeout=None):
  self.consumer = consumer
  self.test_producer = kafka_producer(options)
  self.topic_name = topic_name
- self.timeout = timeout or 1
+ self.timeout = timeout or 2
 
  # Connect to the topic and poll a first test message.
  # First poll takes forever, the next ones are fast.