Fix KafkaSource validation error for missing bootstrapServers (#1051)
Fix KafkaSource validation error for missing bootstrapServers (#1051)

Signed-off-by: Pierangelo Di Pilato <f5f1d2015efd0bb51da99f56609dc938930158a7@redhat.com>
knative-sandbox/eventing-kafka,knative-sandbox/eventing-kafka