Update web_server_configuration.rst

Fixes for issue #4527
https://github.com/symfony/symfony-docs/issues/4527
Update web_server_configuration.rst

Commented the fix for PHP-FPM in Apache VirtualHost
More detailed comments
feature #4528 Update web_server_configuration.rst (thePanz)

This PR was submitted for the master branch but it was merged into the 2.3 branch instead (closes #4528).

Discussion
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Update web_server_configuration.rst

Fixes for issue #4527

Commits
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f70dbf1 Update web_server_configuration.rst
0065791 Update web_server_configuration.rst