Add URI in FPM logs

[mikhainin]

One more patch from our internal repository.

When an error happens, it may be useful to know what request was processed.

Examples from our logs:

WARNING: [pool default] child 3671124 said into stderr: "ERROR: Unable to open primary script: /local/deploy/shot-active/patch-104041/www/404.phtml (No such file or directory) URI: patch-104041.shot.devel/404.phtml"
WARNING: [pool default] child 2148804 said into stderr: "ERROR: status: unable to find or access status shared memory URI: www5/php-fpm-status"

[bukka]

This looks a bit hacky to me and not something that we should accept in the current form. I think much better solution would be to re-use the logic from access.format and allow formatting for log message (child logging through external logger). I have got some plans to look to consolidating access log and zlog in the future to allow longer access log messages so then it could be extended to allow formatting for error messages as well. This would be also more generic and would allow more things to be added.

[mikhainin]

Thanks for your comment. I'll take a look into how we can make it better