Add try catch to ph5avialbility.

[timronan]

Thank your for contributing to PH5

Before submitting a PR, please review the pull request guidelines: https://github.com/PIC-IRIS/PH5/blob/master/CONTRIBUTING.md#submitting-a-pull-request

What does this PR do?

Relevant Issues?

Checklist

• [ ] This PR is not directly related to an existing issue (which has no PR yet).
• [ ] All tests pass.
• [ ] Any new or changed features have are documented.
• [ ] Changes have been added to CHANGELOG.txt .
• [ ] First time contributors have added your name to CONTRIBUTORS.txt .

[damhuonglan]

@timronan I see that you still didn't finish this branch. I will finish this and ask you to have the final review.

[damhuonglan]

@timronan I fixed the key but can't request you to review because you're the owner of the PR. Please have a look and leave your review here. Thanks.

[timronan]

Thanks for fixing that. I am merging now.

[timronan]

@damhuonglan Please re-review and resolve the conversation so I can merge it.