[camera] The old example URL did not have an example.

[gazialankus]

The old example URL did not have an example. Here is what it looked like:

Pre-launch Checklist

• [ x] The title of the PR starts with the name of the plugin surrounded by square brackets, e.g. [shared_preferences]
• [x ] I read the [Contributor Guide] and followed the process outlined there for submitting PRs.
• [ x] I read the [Tree Hygiene] wiki page, which explains my responsibilities.
• [x ] I read and followed the [Flutter Style Guide] and the [C++, Objective-C, Java style guides].
• I listed at least one issue that this PR fixes in the description above.
• I added new tests to check the change I am making or feature I am adding, or Hixie said the PR is test exempt.
• I updated pubspec.yaml with an appropriate new version according to the [pub versioning philosophy].
• I updated CHANGELOG.md to add a description of the change.
• I updated/added relevant documentation (doc comments with ///).
• [ x] I signed the [CLA].
• All existing and new tests are passing.

[mvanbeusekom]

LGTM

[stuartmorgan]

Ah, there ended up being a duplicate of this (#3472) that landed recently. Closing since it's obsolete; thanks for the submission, and sorry we didn't review this before another copy came in.