Suppress the long shell command to test for a file existence so that

[roberthbailey]

it is clearer that not having the file is not an error.

What type of PR is this?

Uncomment only one /kind <> line, hit enter to put that in a new line, and remove leading whitespace from that line:

/kind breaking
/kind bug

/kind cleanup

/kind documentation
/kind feature
/kind hotfix

What this PR does / Why we need it:

Build experience is a bit nicer.

Which issue(s) this PR fixes:
Closes #1039

Special notes for your reviewer:

Old and new output can be seen in #1039 (comment)

[roberthbailey]

/assign @pooneh-m

[roberthbailey]

This PR fits adheres to the list of acceptable changes during feature freeze.

[agones-bot]

Build Succeeded 👏

Build Id: fb756443-699c-4983-8552-ec4f31209699

The following development artifacts have been built, and will exist for the next 30 days:

• image: gcr.io/agones-images/agones-controller:1.14.0-c9dae66
• image: gcr.io/agones-images/agones-ping:1.14.0-c9dae66
• Linux C++ SDK (build): agonessdk-1.14.0-c9dae66-linux-arch_64.tar.gz
• SDK Server: agonessdk-server-1.14.0-c9dae66.zip

A preview of the website (the last 30 builds are retained):

• https://c9dae66-dot-preview-dot-agones-images.appspot.com/

To install this version:

• git fetch https://github.com/googleforgames/agones.git pull/2072/head:pr_2072 && git checkout pr_2072
• helm install ./install/helm/agones --namespace agones-system --name agones --set agones.image.tag=1.14.0-c9dae66