Stop printing dots while retrieving pod in review-apps.sh

What does this MR do?

This should avoid errors such as https://gitlab.com/gitlab-org/gitlab-ce/-/jobs/256820101 and https://gitlab.com/gitlab-org/gitlab-ce/-/jobs/256499740:

** Waiting till 'migrations' pod is ready **
Running 'kubectl get pods -n review-apps-ce --field-selector=status.phase=Running -lapp=migrations,release=review-ce-4946-re-1wb65s --no-headers -o=custom-columns=NAME:.metadata.name'
The pod name couldn't be found after 125 seconds, aborting.
The pod name is ''.
Logs tail of the ......................... pod...
Error from server (NotFound): pods "........................." not found

and

** Waiting till 'unicorn' pod is ready **
Running 'kubectl get pods -n review-apps-ce --field-selector=status.phase=Running -lapp=unicorn,release=review-12-1-auto-ff3xdh --no-headers -o=custom-columns=NAME:.metadata.name'
The pod name is 'review-12-1-auto-ff3xdh-unicorn-89b56cd7b-fhrkr'.
Logs tail of the ..................review-12-1-auto-ff3xdh-unicorn-89b56cd7b-fhrkr pod...
Error from server (NotFound): pods "..................review-12-1-auto-ff3xdh-unicorn-89b56cd7b-fhrkr" not found