Fix/cache key

[ekmst]

Hello!

• Type: bug fix
• Link to issue:

In raising this pull request, I confirm the following:

• I have read and understood the Contributing Guidelines
• I have checked that another pull request for this purpose does not exist
• I wrote some tests for this PR
• I have updated the relevant CHANGELOG
• I have created a PR for the documentation about this change

Small description of change: added missed . to key pattern
see

Thanks

[niden]

@ekmst Thank you for this. If you don't mind update the changelog also.

[niden]

Thank you @ekmst !

[PutinVladimir]

Do not follow blindly PSR.

There told must at least support this chars, but not should be limited this chars and "MAY support additional characters and encodings".
So you limited to cache content of page where page name or page url in national characters as cache key.

Also in PSR told "The following characters are reserved for future extensions and MUST NOT be supported by implementing libraries: {}()/@:" but most of this symbols correctly worked in apcu, memcached, redis and at least ":", "/" needed for whole page caching by url.