Add gone exception hint

[magus0219]

Proposed change

Add obvious hint for Gone (410) occurs after download url of photos expires.

Type of change

• [ ] Dependency upgrade
• [x] Bugfix (non-breaking change which fixes an issue)
• [ ] New service (thank you!)
• [ ] New feature (which adds functionality to an existing service)
• [ ] Breaking change (fix/feature causing existing functionality to break)
• [ ] Code quality improvements to existing code or addition of tests
• [ ] Documentation or code sample

Additional information

• This PR fixes or closes issue: fixes #269
• This PR is related to issue:

Checklist

• [x] The code change is tested and works locally.
• [x] Local tests pass. Your PR cannot be merged unless tests pass
• [x] There is no commented out code in this PR.
• [x] Tests have been added to verify that the new code works.

If user exposed functionality or configuration variables are added/changed:

• [ ] Documentation added/updated to README

[Quentame]

Sorry for being long to review