Jitpack dependency in quickstart refers to main-SNAPSHOT in 1.6.x branch

This issue tracks upstream https://github.com/openshift-integration/camel-k-example-event-streaming/issues/71.

Fix https://github.com/openshift-integration/camel-k-example-event-streaming/commit/5b2ee28c3183fb76235c7fa3db420b1424085156 sets branch to main-SNAPSHOT although it is on 1.6.x branch.